### 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
String scene_file_path = p_node->get_scene_file_path();
	
	if (p_node->get_scene_file_path() == p_instance_path) {
		p_instance_list.push_back(p_node);
	} else {
		Node *current_node = p_node;
		Ref<SceneState> inherited_state = current_node->get_scene_inherited_state();
		while (inherited_state.is_valid()) {
			String inherited_path = inherited_state->get_path();
			if (inherited_path == p_instance_path) {
				p_instance_list.push_back(p_node);
				break;
			}
			inherited_state = inherited_state->get_base_scene_state();
		}
	}
	for (int i = 0; i < p_node->get_child_count(); i++) {
		Node *child = p_node->get_child(i);
		find_all_instances_inheriting_path_in_node(p_root, child, p_instance_path, p_instance_list);
	}
}
void EditorNode::reload_instances_with_path_in_edited_scenes(const String &p_instance_path) {
	int original_edited_scene_idx = editor_data.get_edited_scene();
	HashMap<int, List<Node *>> edited_scene_map;
	
	
	for (int i = 0; i < editor_data.get_edited_scene_count(); i++) {
		if (editor_data.get_scene_path(i) != p_instance_path) {