### Godot version

4.1.1

### System information

linux

### Issue description

[simplescreenrecorder-2023-08-30_15.01.51.webm](https://github.com/godotengine/godot-proposals/assets/71937306/537d92b9-4f98-4fe6-adf4-71297be0471a)

I guess this wasn't the case before since I could save a layout named "2 monitors".

### Steps to reproduce

press space

### Minimal reproduction project

none
case Theme::DATA_TYPE_ICON: {
			ur->add_do_method(*edited_theme, "rename_icon", p_item_name, new_name, edited_type);
			ur->add_undo_method(*edited_theme, "rename_icon", new_name, p_item_name, edited_type);
		} break;
		case Theme::DATA_TYPE_STYLEBOX: {
			ur->add_do_method(*edited_theme, "rename_stylebox", p_item_name, new_name, edited_type);
			ur->add_undo_method(*edited_theme, "rename_stylebox", new_name, p_item_name, edited_type);
			if (leading_stylebox.pinned && leading_stylebox.item_name == p_item_name) {
				leading_stylebox.item_name = new_name;
			}
		} break;
	}
	ur->commit_action();
}
void ThemeTypeEditor::_item_rename_entered(String p_value, int p_data_type, String p_item_name, Control *p_control) {
	_item_rename_confirmed(p_data_type, p_item_name, p_control);
}
void ThemeTypeEditor::_item_rename_canceled(int p_data_type, String p_item_name, Control *p_control) {
	
	Object::cast_to<LineEdit>(p_control->get_child(1))->hide();
	
	Object::cast_to<Button>(p_control->get_child(4))->hide();
	Object::cast_to<Button>(p_control->get_child(5))->hide();
	
	Object::cast_to<Label>(p_control->get_child(0))->show();
	
	Object::cast_to<Button>(p_control->get_child(2))->show();
	Object::cast_to<Button>(p_control->get_child(3))->show();
}
void ThemeTypeEditor::_color_item_changed(Color p_value, String p_item_name) {