### 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
bool show_default = show_default_items_button->is_pressed();
	List<StringName> names;
	focusables.clear();
	
	{
		for (int i = color_items_list->get_child_count() - 1; i >= 0; i--) {
			Node *node = color_items_list->get_child(i);
			node->queue_free();
			color_items_list->remove_child(node);
		}
		HashMap<StringName, bool> color_items = _get_type_items(edited_type, &Theme::get_color_list, show_default);
		for (const KeyValue<StringName, bool> &E : color_items) {
			HBoxContainer *item_control = _create_property_control(Theme::DATA_TYPE_COLOR, E.key, E.value);
			ColorPickerButton *item_editor = memnew(ColorPickerButton);
			item_editor->set_h_size_flags(SIZE_EXPAND_FILL);
			item_control->add_child(item_editor);
			if (E.value) {
				item_editor->set_pick_color(edited_theme->get_color(E.key, edited_type));
				item_editor->connect("color_changed", callable_mp(this, &ThemeTypeEditor::_color_item_changed).bind(E.key));
				item_editor->get_popup()->connect("about_to_popup", callable_mp(EditorNode::get_singleton(), &EditorNode::setup_color_picker).bind(item_editor->get_picker()));
			} else {
				item_editor->set_pick_color(ThemeDB::get_singleton()->get_default_theme()->get_color(E.key, edited_type));
				item_editor->set_disabled(true);
			}
			_add_focusable(item_editor);
			color_items_list->add_child(item_control);
		}
	}