### 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
Ref<InputEventMouseButton> b = p_event;
	
	if (b.is_valid() && b->get_button_index() == MouseButton::LEFT && b->is_pressed() && b->is_double_click() && tool == TOOL_SELECT) {
		List<CanvasItem *> selection = _get_edited_canvas_items();
		if (selection.size() == 1) {
			CanvasItem *ci = selection[0];
			if (!ci->get_scene_file_path().is_empty() && ci != EditorNode::get_singleton()->get_edited_scene()) {
				EditorNode::get_singleton()->open_request(ci->get_scene_file_path());
				return true;
			}
		}
	}
	return false;
}
bool CanvasItemEditor::_gui_input_anchors(const Ref<InputEvent> &p_event) {
	Ref<InputEventMouseButton> b = p_event;
	Ref<InputEventMouseMotion> m = p_event;
	
	if (drag_type == DRAG_NONE) {
		if (b.is_valid() && b->get_button_index() == MouseButton::LEFT && b->is_pressed() && tool == TOOL_SELECT) {
			List<CanvasItem *> selection = _get_edited_canvas_items();
			if (selection.size() == 1) {
				Control *control = Object::cast_to<Control>(selection[0]);
				if (control && _is_node_movable(control)) {
					Vector2 anchor_pos[4];
					anchor_pos[0] = Vector2(control->get_anchor(SIDE_LEFT), control->get_anchor(SIDE_TOP));