### Godot version

v4.0.beta17.mono.official [c40020513]

### System information

Window 11, Forward+, GTX 1060

### Issue description

Adding two theme variations in a row result to a  crash.

https://user-images.githubusercontent.com/93253123/217037249-1ce1d56d-beb6-4435-83ad-9f8a07fe0e96.mp4



### Steps to reproduce

1. Create a project.
2. Create a theme.
3. Double click to go in the theme editor.
4. Click on manage items buttons.
5. In the add type field type a name to add a type.
6. type another name to add a second type.
7. Crash.

### Minimal reproduction project

[ThemeVariationCrash.zip](https://github.com/godotengine/godot/files/10665863/ThemeVariationCrash.zip)

ClassDB::get_linked_properties_info(object->get_class_name(), p_name, &linked_properties);
		for (const StringName &linked_prop : linked_properties) {
			valid = false;
			Variant undo_value = object->get(linked_prop, &valid);
			if (valid) {
				undo_redo->add_undo_property(object, linked_prop, undo_value);
			}
		}
		PackedStringArray linked_properties_dynamic = object->call("_get_linked_undo_properties", p_name, p_value);
		for (int i = 0; i < linked_properties_dynamic.size(); i++) {
			valid = false;
			Variant undo_value = object->get(linked_properties_dynamic[i], &valid);
			if (valid) {
				undo_redo->add_undo_property(object, linked_properties_dynamic[i], undo_value);
			}
		}
		Variant v_undo_redo = undo_redo;
		Variant v_object = object;
		Variant v_name = p_name;
		for (int i = 0; i < EditorNode::get_singleton()->get_editor_data().get_undo_redo_inspector_hook_callback().size(); i++) {
			const Callable &callback = EditorNode::get_singleton()->get_editor_data().get_undo_redo_inspector_hook_callback()[i];
			const Variant *p_arguments[] = { &v_undo_redo, &v_object, &v_name, &p_value };
			Variant return_value;
			Callable::CallError call_error;
			callback.callp(p_arguments, 4, return_value, call_error);
			if (call_error.error != Callable::CallError::CALL_OK) {
				ERR_PRINT("Invalid UndoRedo callback.");
			}
		}
		if (p_refresh_all) {