The queue backend definition for the queue worker in settings.php file is deprecated

Before:

// ...
// Content of settings.php file.
$settings['queue_service_' . $queue_worker_id] = \Drupal\Core\Queue\QueueDatabaseFactory::class;
//...

After:

// ...
// Content of queue worker plugin file.

/**
 * Process a queue of media items to fetch their thumbnails.
 */
#[QueueWorker(
  id: 'media_entity_thumbnail',
  title: new TranslatableMarkup('Thumbnail downloader'),
  cron: ['time' => 60],
  queue_service: \Drupal\Core\Queue\QueueDatabaseFactory::class,
)]
class ThumbnailDownloader extends QueueWorkerBase implements ContainerFactoryPluginInterface {
// ...

Altering capabilities
Now, as the service name is part of the queue worker plugin definition information, it can be altered via the queue plugin manager hook_info:

#[Hook('queue_info_alter')]
public static function queueInfoAlter(array &$queues): void {
  $queues['media_entity_thumbnail']['queue_service'] = \Drupal\Core\Queue\QueueDatabaseFactory::class;
}

Changes in the class definition:
Class Drupal\Core\Queue\QueueFactory now takes the QueueWorkerManagerInterface dependency in the constructor as a new argument.