### 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
ur->add_do_method(*edited_theme, "set_color", p_item_name, p_item_type, Color());
			ur->add_undo_method(*edited_theme, "clear_color", p_item_name, p_item_type);
			break;
		case Theme::DATA_TYPE_CONSTANT:
			ur->add_do_method(*edited_theme, "set_constant", p_item_name, p_item_type, 0);
			ur->add_undo_method(*edited_theme, "clear_constant", p_item_name, p_item_type);
			break;
		case Theme::DATA_TYPE_MAX:
			break; 
	}
	ur->add_do_method(this, "_update_edit_item_tree", edited_item_type);
	ur->add_undo_method(this, "_update_edit_item_tree", edited_item_type);
	ur->commit_action();
}
void ThemeItemEditorDialog::_remove_theme_type(const String &p_theme_type) {
	Ref<Theme> old_snapshot = edited_theme->duplicate();
	Ref<Theme> new_snapshot = edited_theme->duplicate();
	EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
	ur->create_action(TTR("Remove Theme Type"));
	new_snapshot->remove_type(p_theme_type);
	ur->add_do_method(*edited_theme, "clear");
	ur->add_do_method(*edited_theme, "merge_with", new_snapshot);
	
	ur->add_undo_method(*edited_theme, "add_type", p_theme_type);
	ur->add_undo_method(*edited_theme, "merge_with", old_snapshot);
	ur->add_do_method(this, "_update_edit_types");
	ur->add_undo_method(this, "_update_edit_types");
	ur->commit_action();
}
void ThemeItemEditorDialog::_remove_data_type_items(Theme::DataType p_data_type, String p_item_type) {