### 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
} else if (_gui_input_rotate(p_event)) {
			
		} else if (_gui_input_move(p_event)) {
			
		} else if (_gui_input_anchors(p_event)) {
			
		} else if (_gui_input_select(p_event)) {
			
		} else if (_gui_input_ruler_tool(p_event)) {
			
		} else {
			
			accepted = false;
		}
	}
	accepted = (_gui_input_zoom_or_pan(p_event, accepted) || accepted);
	if (accepted) {
		accept_event();
	}
	
	_gui_input_hover(p_event);
	
	_update_cursor();
	
	if (!viewport->has_focus() && (!get_viewport()->gui_get_focus_owner() || !get_viewport()->gui_get_focus_owner()->is_text_field())) {
		viewport->call_deferred(SNAME("grab_focus"));
	}
}
void CanvasItemEditor::_update_cursor() {