### 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
add_type_filter->set_text("");
	add_type_filter->grab_focus();
	_update_add_type_options();
}
void ThemeTypeDialog::ok_pressed() {
	_add_type_selected(add_type_filter->get_text().strip_edges());
}
void ThemeTypeDialog::_update_add_type_options(const String &p_filter) {