### Godot version

4.0 beta 15

### System information

Windows 10

### Issue description

It happened with both Google IME and MS-IME, and there was no problem until Beta14.
When typing Japanese characters, it is common to select a character from the suggestion window and then start typing the next character before confirming.
In this case, uncommitted characters are forcibly committed, and input of the next character begins.

**↓Beta15**

https://user-images.githubusercontent.com/186786/214753450-b493cca6-2644-4b3d-8cd2-660565cc3547.mp4

**↓Beta14**

https://user-images.githubusercontent.com/186786/214755127-dde819cc-4d63-403a-99b0-09821671f74e.mp4



### Steps to reproduce

It happened with both Google IME and MS-IME in beta15

### Minimal reproduction project

It is project independent and happens in the editor.
float char_w = font->get_char_size(' ', font_size).width;
								if (rtl) {
									RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(size.width - xmargin_beg - ofs_x - char_w, ofs_y, char_w, row_height), selection_color);
								} else {
									RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(xmargin_beg + ofs_x, ofs_y, char_w, row_height), selection_color);
								}
							}
						}
					} else {
						
						if (caret_line_wrap_index_map.has(line) && caret_line_wrap_index_map[line].has(line_wrap_index) && highlight_current_line) {
							if (rtl) {
								RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(size.width - ofs_x - xmargin_end, ofs_y, xmargin_end, row_height), current_line_color);
							} else {
								RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(ofs_x, ofs_y, xmargin_end, row_height), current_line_color);
							}
						}
					}
					if (line_wrap_index == 0) {
						
						cache_entry.y_offset = ofs_y;
						int gutter_offset = style_normal->get_margin(SIDE_LEFT);
						for (int g = 0; g < gutters.size(); g++) {
							const GutterInfo gutter = gutters[g];
							if (!gutter.draw || gutter.width <= 0) {
								continue;
							}
							switch (gutter.type) {
								case GUTTER_TYPE_STRING: {
									const String &txt = get_line_gutter_text(line, g);