Issue #3300194 by e0ipso: Remove warning on the widget dropdown

  array_walk($options, static function (array &$option_group): void {

    asort($option_group);

  });

  if (!empty($options[$no_registry_source])) {

    // Move the 'Other' option group (for widget types with no registry source)

    // to the bottom of the select list.

    $options[(string) new TranslatableMarkup('Other')] = $options[$no_registry_source];

    unset($options[$no_registry_source]);

  }

}