### 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_focusable(item_editor);
			icon_items_list->add_child(item_control);
		}
	}
	
	{
		for (int i = stylebox_items_list->get_child_count() - 1; i >= 0; i--) {
			Node *node = stylebox_items_list->get_child(i);
			node->queue_free();
			stylebox_items_list->remove_child(node);
		}
		if (leading_stylebox.pinned) {
			HBoxContainer *item_control = _create_property_control(Theme::DATA_TYPE_STYLEBOX, leading_stylebox.item_name, true);
			EditorResourcePicker *item_editor = memnew(EditorResourcePicker);
			item_editor->set_h_size_flags(SIZE_EXPAND_FILL);
			item_editor->set_stretch_ratio(1.5);
			item_editor->set_base_type("StyleBox");
			Button *pin_leader_button = memnew(Button);
			pin_leader_button->set_flat(true);
			pin_leader_button->set_toggle_mode(true);
			pin_leader_button->set_pressed(true);
			pin_leader_button->set_icon(get_theme_icon(SNAME("Pin"), SNAME("EditorIcons")));
			pin_leader_button->set_tooltip_text(TTR("Unpin this StyleBox as a main style."));
			item_control->add_child(pin_leader_button);
			pin_leader_button->connect("pressed", callable_mp(this, &ThemeTypeEditor::_on_unpin_leader_button_pressed));
			item_control->add_child(item_editor);
			if (edited_theme->has_stylebox(leading_stylebox.item_name, edited_type)) {
				item_editor->set_edited_resource(leading_stylebox.stylebox);
			} else {