### 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
deselect_all_colors_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_colors_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_colors_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_constants_icon->set_texture(get_theme_icon(SNAME("MemberConstant"), SNAME("EditorIcons")));
			deselect_all_constants_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_constants_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_constants_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_fonts_icon->set_texture(get_theme_icon(SNAME("Font"), SNAME("EditorIcons")));
			deselect_all_fonts_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_fonts_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_fonts_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_font_sizes_icon->set_texture(get_theme_icon(SNAME("FontSize"), SNAME("EditorIcons")));
			deselect_all_font_sizes_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_font_sizes_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_font_sizes_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_icons_icon->set_texture(get_theme_icon(SNAME("ImageTexture"), SNAME("EditorIcons")));
			deselect_all_icons_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_icons_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_icons_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_styleboxes_icon->set_texture(get_theme_icon(SNAME("StyleBoxFlat"), SNAME("EditorIcons")));
			deselect_all_styleboxes_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_styleboxes_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_styleboxes_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
		} break;
	}
}
void ThemeItemImportTree::_bind_methods() {
	ADD_SIGNAL(MethodInfo("items_imported"));
}
ThemeItemImportTree::ThemeItemImportTree() {