Fix event dispatching for drupal core 10

This looks good to me.

The only thing is we are per the info file still compatible with Drupal 9.x here. Is it allowed to pass them in that order on Drupal 9? Just asking since I don't have it in front of me, and I think it is?

Yes.
D9:

/**
   * {@inheritdoc}
   */
  public function dispatch($event/*, string $event_name = NULL*/) {
    $event_name = 1 < \func_num_args() ? func_get_arg(1) : NULL;

D10:

/**
   * {@inheritdoc}
   */
  public function dispatch(object $event, ?string $eventName = NULL): object {
    $event_name = $eventName ?? get_class($event);

Automatically closed - issue fixed for 2 weeks with no activity.