### Godot version

v4.2.dev.custom_build [0c2144da9]

### System information

Debian Linux X11 Xfce

### Issue description

Prerequisite: Be in Single Window Mode in the Editor
The Filesystem Dock is unusable when it is floating, which is not expected.
It appears garbled in the top-left corner:
![image](https://github.com/godotengine/godot/assets/6299227/109f7922-97de-44c3-814a-ca7f970e0602)

The following errors are shown:
```
  editor/window_wrapper.cpp:220 - Condition "!is_window_available()" is true.
  editor/window_wrapper.cpp:202 - Condition "!get_window_enabled()" is true. Returning: Rect2i()
  editor/window_wrapper.cpp:207 - Condition "!get_window_enabled()" is true. Returning: -1
  editor/window_wrapper.cpp:207 - Condition "!get_window_enabled()" is true. Returning: -1
```

bisecting lead to #62378
possibly related to #44439

### Steps to reproduce

1. Start a project in the Editor
2. Switch to Single Window Mode in the Editor and reload (if necessary)
3. Make the Filesystem Dock floating

### Minimal reproduction project

Editor issue
}
	if (editor_plugin_screen) {
		editor_plugin_screen->make_visible(false);
	}
	editor_plugin_screen = new_editor;
	editor_plugin_screen->make_visible(true);
	editor_plugin_screen->selected_notify();
	int plugin_count = editor_data.get_editor_plugin_count();
	for (int i = 0; i < plugin_count; i++) {
		editor_data.get_editor_plugin(i)->notify_main_screen_changed(editor_plugin_screen->get_name());
	}
	if (EDITOR_GET("interface/editor/separate_distraction_mode")) {
		if (p_which == EDITOR_SCRIPT) {
			set_distraction_free_mode(script_distraction_free);
		} else {
			set_distraction_free_mode(scene_distraction_free);
		}
	}
}
void EditorNode::select_editor_by_name(const String &p_name) {
	ERR_FAIL_COND(p_name.is_empty());
	for (int i = 0; i < main_editor_buttons.size(); i++) {
		if (main_editor_buttons[i]->get_text() == p_name) {
			editor_select(i);
			return;
		}
	}
	ERR_FAIL_MSG("The editor name '" + p_name + "' was not found.");
}
void EditorNode::add_editor_plugin(EditorPlugin *p_editor, bool p_config_changed) {