### 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
case Variant::ARRAY: {
				Array varray = obj->get(E.name);
				int len = varray.size();
				for (int i = 0; i < len; i++) {
					const Variant &v = varray.get(i);
					Ref<Resource> res = v;
					if (_find_and_save_resource(res, processed, flags)) {
						ret_changed = true;
					}
				}
			} break;
			case Variant::DICTIONARY: {
				Dictionary d = obj->get(E.name);
				List<Variant> keys;
				d.get_key_list(&keys);
				for (const Variant &F : keys) {
					Variant v = d[F];
					Ref<Resource> res = v;
					if (_find_and_save_resource(res, processed, flags)) {
						ret_changed = true;
					}
				}
			} break;
			default: {
			}
		}
	}
	return ret_changed;
}
void EditorNode::_save_edited_subresources(Node *scene, HashMap<Ref<Resource>, bool> &processed, int32_t flags) {