The DrupalQueue system was refactored to use a different factory, for consistency with other similar subsystems (cache, db).
$queue = DrupalQueue::get('update_fetch_tasks');
$queue = Drupal::queue('update_fetch_tasks');
By default, the queue service uses the queue.database implementation, which can be controlled by the following $settings in settings.php:
queue_reliable_service_' . $name: A reliable queue for the $name queue queue_service_' . $name: A queue for the $name queue queue_default: The default queue backend service, defaults to queue.database