fix: remove exception on delete event (#1681)

Author: csviri

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/source/controller/ControllerResourceEventSource.java

@@ -94,8 +94,6 @@ private boolean isAcceptedByFilters(ResourceAction action, T resource, T oldReso
         return onAddFilter == null || onAddFilter.accept(resource);
       case UPDATED:
         return onUpdateFilter.accept(resource, oldResource);
-      case DELETED:
-        throw new IllegalStateException("Should not be called with " + action);
     }
     return true;
   }