handle error in case ownerRef is not set on crs binding

exp/addons/internal/controllers/clusterresourcesetbinding_controller.go

@@ -80,7 +80,11 @@ func (r *ClusterResourceSetBindingReconciler) Reconcile(ctx context.Context, req
 	if err != nil && !apierrors.IsNotFound(err) {
 		return ctrl.Result{}, err
 	}
-
+	if err == nil && cluster == nil {
+		log.Info("ownerRef not found for the ClusterResourceSetBinding")
+		// requeue the request
+		return ctrl.Result{}, nil
+	}
 	// If the owner cluster is already deleted or in deletion process, delete its ClusterResourceSetBinding
 	if apierrors.IsNotFound(err) || !cluster.DeletionTimestamp.IsZero() {
 		log.Info("deleting ClusterResourceSetBinding because the owner Cluster no longer exists")