fix: register retry event source after event handler is created

Author: metacosm

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/EventSourceManager.java

@@ -45,11 +45,14 @@ public class EventSourceManager<R extends HasMetadata> implements LifecycleAware
 
   public EventSourceManager(Controller<R> controller) {
     this.controller = controller;
-    registerEventSource(eventSources.initRetryEventSource());
 
     // controller event source needs to be available before we create the event processor
     final var controllerEventSource = eventSources.initControllerEventSource(controller);
     this.eventProcessor = new EventProcessor<>(this);
+
+    // sources need to be registered after the event processor is created since it's set on the
+    // event source
+    registerEventSource(eventSources.initRetryEventSource());
     registerEventSource(controllerEventSource);
   }