### 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
export_template_manager->install_android_template_from_file(p_file);
}
void EditorNode::_menu_option_confirm(int p_option, bool p_confirmed) {
	if (!p_confirmed) { 
		current_menu_option = (MenuOptions)p_option;
	}
	switch (p_option) {
		case FILE_NEW_SCENE: {
			new_scene();
		} break;
		case FILE_NEW_INHERITED_SCENE:
		case FILE_OPEN_SCENE: {
			file->set_file_mode(EditorFileDialog::FILE_MODE_OPEN_FILE);
			List<String> extensions;
			ResourceLoader::get_recognized_extensions_for_type("PackedScene", &extensions);
			file->clear_filters();
			for (int i = 0; i < extensions.size(); i++) {
				file->add_filter("*." + extensions[i], extensions[i].to_upper());
			}
			Node *scene = editor_data.get_edited_scene_root();
			if (scene) {
				file->set_current_path(scene->get_scene_file_path());
			};
			file->set_title(p_option == FILE_OPEN_SCENE ? TTR("Open Scene") : TTR("Open Base Scene"));
			file->popup_file_dialog();
		} break;
		case FILE_QUICK_OPEN: {
			quick_open->popup_dialog("Resource", true);