### 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
import_items_filter = memnew(LineEdit);
	import_items_filter->set_placeholder(TTR("Filter Items"));
	import_items_filter->set_clear_button_enabled(true);
	add_child(import_items_filter);
	import_items_filter->connect("text_changed", callable_mp(this, &ThemeItemImportTree::_filter_text_changed));
	HBoxContainer *import_main_hb = memnew(HBoxContainer);
	import_main_hb->set_v_size_flags(Control::SIZE_EXPAND_FILL);
	add_child(import_main_hb);
	import_items_tree = memnew(Tree);
	import_items_tree->set_hide_root(true);
	import_items_tree->set_h_size_flags(Control::SIZE_EXPAND_FILL);
	import_main_hb->add_child(import_items_tree);
	import_items_tree->connect("item_edited", callable_mp(this, &ThemeItemImportTree::_tree_item_edited));
	import_items_tree->connect("check_propagated_to_item", callable_mp(this, &ThemeItemImportTree::_check_propagated_to_tree_item));
	import_items_tree->set_columns(3);
	import_items_tree->set_column_titles_visible(true);
	import_items_tree->set_column_title(IMPORT_ITEM, TTR("Import"));
	import_items_tree->set_column_title(IMPORT_ITEM_DATA, TTR("With Data"));
	import_items_tree->set_column_expand(0, true);
	import_items_tree->set_column_clip_content(0, true);
	import_items_tree->set_column_expand(IMPORT_ITEM, false);
	import_items_tree->set_column_expand(IMPORT_ITEM_DATA, false);
	import_items_tree->set_column_custom_minimum_width(0, 160 * EDSCALE);
	import_items_tree->set_column_custom_minimum_width(IMPORT_ITEM, 80 * EDSCALE);
	import_items_tree->set_column_custom_minimum_width(IMPORT_ITEM_DATA, 80 * EDSCALE);
	import_items_tree->set_column_clip_content(1, true);
	import_items_tree->set_column_clip_content(2, true);
	ScrollContainer *import_bulk_sc = memnew(ScrollContainer);