### Godot version

v4.0.beta.custom_build [eaf306e0b]

### System information

Windows 10

### Issue description

Selecting a `Window` node in the Editor's SceneTree results in the message
```
editor/editor_data.cpp:1058 - Parameter "p_node" is null.
```
and the Inspector shows empty content instead of the Window's properties.

I would expect, that clicking on a node in the SceneTree lets me edit the properties of the node.

Bisecting shows that this behavior got introduced in #71770

### Steps to reproduce

1. Create a Window node
2. Click on the Window node in the Editor's SceneTree

### Minimal reproduction project

N/A
Error err = EditorNode::get_singleton()->load_scene(path, false, true);
				if (err != OK) {
					error_files.push_back(path);
				}
			} else {
				bool success = _create_instance(target_node, path, drop_pos);
				if (!success) {
					error_files.push_back(path);
				}
			}
		} else {
			Ref<Texture2D> texture = Ref<Texture2D>(Object::cast_to<Texture2D>(*res));
			if (texture != nullptr && texture.is_valid()) {
				Node *child = _make_texture_node_type(default_texture_node_type);
				_create_nodes(target_node, child, path, drop_pos);
			}
		}
	}
	undo_redo->commit_action();
	if (error_files.size() > 0) {
		String files_str;
		for (int i = 0; i < error_files.size(); i++) {
			files_str += error_files[i].get_file().get_basename() + ",";
		}
		files_str = files_str.substr(0, files_str.length() - 1);
		accept->set_text(vformat(TTR("Error instantiating scene from %s"), files_str.get_data()));
		accept->popup_centered();
	}
}
bool CanvasItemEditorViewport::can_drop_data(const Point2 &p_point, const Variant &p_data) const {