### 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
res->set_edited(false);
	}
	for (const String &E : edited_resources) {
		Ref<Resource> res = ResourceCache::get_ref(E);
		if (!res.is_valid()) {
			continue; 
		}
		Ref<PackedScene> ps = res;
		if (ps.is_valid()) {
			continue; 
		}
		ResourceSaver::save(res, res->get_path(), flg);
		saved++;
	}
	EditorUndoRedoManager::get_singleton()->set_history_as_saved(EditorUndoRedoManager::GLOBAL_HISTORY);
	return saved;
}
static void _reset_animation_players(Node *p_node, List<Ref<AnimatedValuesBackup>> *r_anim_backups) {
	for (int i = 0; i < p_node->get_child_count(); i++) {
		AnimationPlayer *player = Object::cast_to<AnimationPlayer>(p_node->get_child(i));
		if (player && player->is_reset_on_save_enabled() && player->can_apply_reset()) {
			Ref<AnimatedValuesBackup> old_values = player->apply_reset();
			if (old_values.is_valid()) {
				r_anim_backups->push_back(old_values);
			}
		}
		_reset_animation_players(p_node->get_child(i), r_anim_backups);
	}
}
void EditorNode::_save_scene(String p_file, int idx) {