### 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
break;
			}
		}
		
		if (!ci || duplicate || (ci != scene && ci->get_owner() != scene && !scene->is_editable_instance(ci->get_owner())) || (!p_allow_locked && _is_node_locked(ci))) {
			r_items.remove_at(i);
			i--;
		} else {
			r_items.write[i].item = ci;
		}
	}
}
void CanvasItemEditor::_find_canvas_items_in_rect(const Rect2 &p_rect, Node *p_node, List<CanvasItem *> *r_items, const Transform2D &p_parent_xform, const Transform2D &p_canvas_xform) {
	if (!p_node) {
		return;
	}
	if (Object::cast_to<Viewport>(p_node)) {
		return;
	}
	CanvasItem *ci = Object::cast_to<CanvasItem>(p_node);
	Node *scene = EditorNode::get_singleton()->get_edited_scene();
	bool editable = p_node == scene || p_node->get_owner() == scene || p_node == scene->get_deepest_editable_node(p_node);
	bool lock_children = p_node->get_meta("_edit_group_", false);
	bool locked = _is_node_locked(p_node);
	if (!lock_children || !editable) {
		for (int i = p_node->get_child_count() - 1; i >= 0; i--) {
			if (ci) {
				if (!ci->is_set_as_top_level()) {
					_find_canvas_items_in_rect(p_rect, p_node->get_child(i), r_items, p_parent_xform * ci->get_transform(), p_canvas_xform);
				} else {