### 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
}
	{
		names.clear();
		ThemeDB::get_singleton()->get_default_theme()->get_color_list(default_type, &names);
		for (const StringName &E : names) {
			if (!new_snapshot->has_color(E, edited_type)) {
				new_snapshot->set_color(E, edited_type, ThemeDB::get_singleton()->get_default_theme()->get_color(E, edited_type));
			}
		}
	}
	{
		names.clear();
		ThemeDB::get_singleton()->get_default_theme()->get_constant_list(default_type, &names);
		for (const StringName &E : names) {
			if (!new_snapshot->has_constant(E, edited_type)) {
				new_snapshot->set_constant(E, edited_type, ThemeDB::get_singleton()->get_default_theme()->get_constant(E, edited_type));
			}
		}
	}
	updating = false;
	EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
	ur->create_action(TTR("Override All Default Theme Items"));
	ur->add_do_method(*edited_theme, "merge_with", new_snapshot);
	ur->add_undo_method(*edited_theme, "clear");
	ur->add_undo_method(*edited_theme, "merge_with", old_snapshot);
	ur->add_do_method(this, "_update_type_items");
	ur->add_undo_method(this, "_update_type_items");
	ur->commit_action();
}
void ThemeTypeEditor::_item_add_cbk(int p_data_type, Control *p_control) {