### 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
select_items_label = select_styleboxes_label;
				deselect_all_items_button = deselect_all_styleboxes_button;
				select_all_items_button = select_all_styleboxes_button;
				select_full_items_button = select_full_styleboxes_button;
				total_selected_items_label = total_selected_styleboxes_label;
				items_title = TTR("Styleboxes");
				select_all_items_tooltip = TTR("Select all visible stylebox items.");
				select_full_items_tooltip = TTR("Select all visible stylebox items and their data.");
				deselect_all_items_tooltip = TTR("Deselect all visible stylebox items.");
				break;
			case Theme::DATA_TYPE_MAX:
				continue; 
		}
		if (i > 0) {
			import_bulk_vb->add_child(memnew(HSeparator));
		}
		HBoxContainer *all_set = memnew(HBoxContainer);
		import_bulk_vb->add_child(all_set);
		HBoxContainer *label_set = memnew(HBoxContainer);
		label_set->set_h_size_flags(Control::SIZE_EXPAND_FILL);
		all_set->add_child(label_set);
		select_items_icon->set_v_size_flags(Control::SIZE_SHRINK_CENTER);
		label_set->add_child(select_items_icon);
		select_items_label->set_h_size_flags(Control::SIZE_EXPAND_FILL);
		select_items_label->set_clip_text(true);
		select_items_label->set_text(items_title);
		label_set->add_child(select_items_label);
		HBoxContainer *button_set = memnew(HBoxContainer);
		button_set->set_alignment(BoxContainer::ALIGNMENT_END);
		all_set->add_child(button_set);