### Godot version

3.5.1mono

### System information

windows10

### Issue description

Error message
 scene/main/node.cpp:1362 - Index p_index = 0 is out of bounds (data.children.size() = 0).
 scene/main/node.cpp:397 - Parameter "p_child" is null.
 scene/gui/tab_container.cpp:593 - Index p_current = 0 is out of bounds (get_tab_count() = 0).
See "Steps to reproduce for details"

### Steps to reproduce

Set an external text editor
Create a script
Drop the script to the built-in text editor like this image:
![image](https://user-images.githubusercontent.com/119792950/209504041-039f2620-5e42-4c0f-8c41-cd24486fb3d2.png)
And got error message:
 scene/main/node.cpp:1362 - Index p_index = 0 is out of bounds (data.children.size() = 0).
 scene/main/node.cpp:397 - Parameter "p_child" is null.
 scene/gui/tab_container.cpp:593 - Index p_current = 0 is out of bounds (get_tab_count() = 0).

### Minimal reproduction project

An empty project
se->set_syntax_highlighter(highlighter);
					highlighter_set = true;
				}
			}
		}
	}
	tab_container->add_child(se);
	if (p_grab_focus) {
		se->enable_editor(this);
	}
	
	
	se->set_meta("_edit_res_path", p_resource->get_path());
	se->set_tooltip_request_func(callable_mp(this, &ScriptEditor::_get_debug_tooltip));
	if (se->get_edit_menu()) {
		se->get_edit_menu()->hide();
		menu_hb->add_child(se->get_edit_menu());
		menu_hb->move_child(se->get_edit_menu(), 1);
	}
	if (p_grab_focus) {
		_go_to_tab(tab_container->get_tab_count() - 1);
		_add_recent_script(p_resource->get_path());
	}
	if (script_editor_cache->has_section(p_resource->get_path())) {
		se->set_edit_state(script_editor_cache->get_value(p_resource->get_path(), "state"));
	}
	_sort_list_on_update = true;
	_update_script_names();
	_save_layout();
	se->connect("name_changed", callable_mp(this, &ScriptEditor::_update_script_names));