### Godot version

4.0.dev Beta 14

### System information

Windows 10 and Linux (Pop!_OS 22.04)

### Issue description

When opening a UTF-8 text file with an emoji or other unicode character, the line will not show up and the editor starts producing a number of errors in output. Here is the output:

--- GDScript language server started ---
  U_ILLEGAL_ARGUMENT_ERROR
  modules/text_server_adv/text_server_adv.cpp:4389 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5829 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  U_ILLEGAL_ARGUMENT_ERROR
  modules/text_server_adv/text_server_adv.cpp:4389 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()

### Steps to reproduce

Add a text file and paste in an emoji into the text resource file then open it in the editor.

### Minimal reproduction project

[FileIOGuide.zip](https://github.com/godotengine/godot/files/10477742/FileIOGuide.zip)

if ((font_style & TextServer::FONT_ITALIC) && ftr.has(ital_tag)) {
							var[ital_tag] = 1;
							_font_set_style(sysf.rid, _font_get_style(sysf.rid) | TextServer::FONT_ITALIC);
						}
					}
					_font_set_antialiasing(sysf.rid, key.antialiasing);
					_font_set_generate_mipmaps(sysf.rid, key.mipmaps);
					_font_set_multichannel_signed_distance_field(sysf.rid, key.msdf);
					_font_set_msdf_pixel_range(sysf.rid, key.msdf_range);
					_font_set_msdf_size(sysf.rid, key.msdf_source_size);
					_font_set_fixed_size(sysf.rid, key.fixed_size);
					_font_set_force_autohinter(sysf.rid, key.force_autohinter);
					_font_set_hinting(sysf.rid, key.hinting);
					_font_set_subpixel_positioning(sysf.rid, key.subpixel_positioning);
					_font_set_variation_coordinates(sysf.rid, var);
					_font_set_oversampling(sysf.rid, key.oversampling);
					_font_set_embolden(sysf.rid, key.embolden);
					_font_set_transform(sysf.rid, key.transform);
					if (system_fonts.has(key)) {
						system_fonts[key].var.push_back(sysf);
					} else {
						SystemFontCache &sysf_cache = system_fonts[key];
						sysf_cache.max_var = _font_get_face_count(sysf.rid);
						sysf_cache.var.push_back(sysf);
					}
					f = sysf.rid;
				}
				
			}
		}