### 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
break;
		case Theme::DATA_TYPE_ICON:
			total_selected_items_label = total_selected_icons_label;
			break;
		case Theme::DATA_TYPE_STYLEBOX:
			total_selected_items_label = total_selected_styleboxes_label;
			break;
		case Theme::DATA_TYPE_MAX:
			return; 
	}
	if (!total_selected_items_label) {
		return;
	}
	int count = 0;
	for (const KeyValue<ThemeItem, ItemCheckedState> &E : selected_items) {
		ThemeItem ti = E.key;
		if (ti.data_type == p_data_type) {
			count++;
		}
	}
	if (count == 0) {
		total_selected_items_label->hide();
	} else {
		Array arr;
		arr.push_back(count);
		total_selected_items_label->set_text(TTRN("{num} currently selected", "{num} currently selected", count).format(arr, "{num}"));
		total_selected_items_label->show();
	}
}
void ThemeItemImportTree::_tree_item_edited() {