title: PostUpdateEventListener not being called
body: <p>I am trying to implement some logic where on one entity update I need to update a field on another entity. I would like to do that in post update listener. 
  I have my code setup as below, however my <code>onPostUpdate</code> handler isn't getting called. What am I doing wrong ?
  In my test code I am calling <code>documentRepository.save(documentEntity)</code>. </p>
  
  <p>( I have tried the same approach with POST_INSERT and PostInsertEventListener, and that worked just fine. My handler was called) </p>
  
  <pre><code>
  @Component
  public class DocumentUpdateListener implements PostUpdateEventListener {
  
      @Override
      public void onPostUpdate(PostUpdateEvent event) {
  
          ... //some business logic here
      }
  
  
      @Override
      public boolean requiresPostCommitHanding(EntityPersister persister) {
          return true;
      }
  
      @Override
      public boolean requiresPostCommitHandling(EntityPersister persister) {
          return true;
      }
  }
  
  @Component
  public class EntityEventListenerRegistry {
  
      @PersistenceUnit
      private EntityManagerFactory emf;
  
      @Autowired
      private DocumentUpdateListener documentUpdateListener;
  
      @PostConstruct
      protected void init() {
          SessionFactoryImpl sessionFactory = emf.unwrap(SessionFactoryImpl.class);
          EventListenerRegistry registry = sessionFactory.getServiceRegistry().getService(EventListenerRegistry.class);
          registry.getEventListenerGroup(EventType.POST_UPDATE).appendListener(documentUpdateListener);
      }
  }
  </code></pre>