### 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 (!item_reselected) {
		edited_item_type = "";
		if (list_root->get_child_count() > 0) {
			list_root->get_child(0)->select(0);
		}
	}
	List<StringName> default_types;
	base_theme->get_type_list(&default_types);
	default_types.sort_custom<StringName::AlphCompare>();
	String selected_type = "";
	TreeItem *selected_item = edit_type_list->get_selected();
	if (selected_item) {
		selected_type = selected_item->get_text(0);
		edit_items_add_color->set_disabled(false);
		edit_items_add_constant->set_disabled(false);
		edit_items_add_font->set_disabled(false);
		edit_items_add_font_size->set_disabled(false);
		edit_items_add_icon->set_disabled(false);
		edit_items_add_stylebox->set_disabled(false);
		edit_items_remove_class->set_disabled(false);
		edit_items_remove_custom->set_disabled(false);
		edit_items_remove_all->set_disabled(false);
		edit_items_message->set_text("");
		edit_items_message->hide();
	} else {
		edit_items_add_color->set_disabled(true);
		edit_items_add_constant->set_disabled(true);
		edit_items_add_font->set_disabled(true);
		edit_items_add_font_size->set_disabled(true);
		edit_items_add_icon->set_disabled(true);