Remove custom updateSelection for views bulk operations

We have been using a custom callback for the updateSelection of ViewsBulkOperationsController

In 12.1.0 we have removed the RouteSubscriber and moved to the ViewsBulkOperationsController one.

We will remove this custom callback in 13.0.0.

It used to be:

class RouteSubscriber extends RouteSubscriberBase {

  /**
   * The list of methods overrides page titles.
   */
  private const CALLBACKS = [
    'views_bulk_operations.update_selection' => SocialCoreController::class . '::updateSelection',
  ];

  /**
   * {@inheritdoc}
   */
  protected function alterRoutes(RouteCollection $collection) {
    foreach (self::CALLBACKS as $route_name => $callback) {
      if ($route = $collection->get($route_name)) {
        $route->setDefault('_controller', $callback);
      }
    }