### 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
}
	} else {
		
		for (int i = 0; i < editor_data.get_editor_plugin_count(); i++) {
			unsaved_message = editor_data.get_editor_plugin(i)->get_unsaved_status(scene_filename);
			if (!unsaved_message.is_empty()) {
				break;
			}
		}
	}
	if (!unsaved_message.is_empty()) {
		if (get_current_tab() != p_tab) {
			set_current_scene(p_tab);
		}
		if (current_menu_option == RELOAD_CURRENT_PROJECT) {
			save_confirmation->set_ok_button_text(TTR("Save & Reload"));
			save_confirmation->set_text(unsaved_message + "\n\n" + TTR("Save before reloading?"));
		} else {
			save_confirmation->set_ok_button_text(TTR("Save & Close"));
			save_confirmation->set_text(unsaved_message + "\n\n" + TTR("Save before closing?"));
		}
		save_confirmation->reset_size();
		save_confirmation->popup_centered();
	} else {
		_discard_changes();
	}
	save_editor_layout_delayed();
	_update_scene_tabs();
}
void EditorNode::_scene_tab_hovered(int p_tab) {