### 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
}
		for (EditorPlugin *plugin : item_plugins) {
			if (active_plugins[owner_id].has(plugin)) {
				plugin->edit(p_object);
				continue;
			}
			for (KeyValue<ObjectID, HashSet<EditorPlugin *>> &kv : active_plugins) {
				if (kv.key != owner_id) {
					EditorPropertyResource *epres = Object::cast_to<EditorPropertyResource>(ObjectDB::get_instance(kv.key));
					if (epres && kv.value.has(plugin)) {
						
						epres->fold_resource();
					}
					kv.value.erase(plugin);
				}
			}
			active_plugins[owner_id].insert(plugin);
			_plugin_over_edit(plugin, p_object);
		}
	} else {
		hide_unused_editors(p_editing_owner);
	}
}
void EditorNode::push_node_item(Node *p_node) {
	if (p_node || Object::cast_to<Node>(InspectorDock::get_inspector_singleton()->get_edited_object()) || Object::cast_to<MultiNodeEdit>(InspectorDock::get_inspector_singleton()->get_edited_object())) {
		
		push_item(p_node);
	}
}
void EditorNode::push_item(Object *p_object, const String &p_property, bool p_inspector_only) {