### 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
if (_is_node_movable(selection2[i], true)) {
						drag_selection.push_back(selection2[i]);
					}
				}
				if (selection2.size() > 0) {
					drag_type = DRAG_MOVE;
					drag_from = drag_start_origin;
					_save_canvas_item_state(drag_selection);
				}
				return true;
			}
		}
	}
	if (drag_type == DRAG_BOX_SELECTION) {
		if (b.is_valid() && !b->is_pressed() && b->get_button_index() == MouseButton::LEFT) {
			
			Node *scene = EditorNode::get_singleton()->get_edited_scene();
			if (scene) {
				List<CanvasItem *> selitems;
				Point2 bsfrom = drag_from;
				Point2 bsto = box_selecting_to;
				if (bsfrom.x > bsto.x) {
					SWAP(bsfrom.x, bsto.x);
				}
				if (bsfrom.y > bsto.y) {
					SWAP(bsfrom.y, bsto.y);
				}
				_find_canvas_items_in_rect(Rect2(bsfrom, bsto - bsfrom), scene, &selitems);
				if (selitems.size() == 1 && editor_selection->get_selected_node_list().is_empty()) {
					EditorNode::get_singleton()->push_item(selitems[0]);