fix TestInformerExistingPodAddErrorAnnotatesWithPartialStatusOnRetry (istio#57830)

The reconcile loop will constantly retry given an error. This can affect
further tests since the reconcile event counter is a global.
Allow the pod to be added to the mesh and no more update events occur.

Author: fraenkel

cni/pkg/nodeagent/informers_test.go

@@ -176,7 +176,7 @@ func TestInformerExistingPodAddErrorAnnotatesWithPartialStatusOnRetry(t *testing
 	client := kube.NewFakeClient(ns, pod)
 	fs := &fakeServer{}
 
-	fs.On("AddPodToMesh",
+	call := fs.On("AddPodToMesh",
 		ctx,
 		mock.IsType(pod),
 		util.GetPodIPsIfPresent(pod),
@@ -201,6 +201,11 @@ func TestInformerExistingPodAddErrorAnnotatesWithPartialStatusOnRetry(t *testing
 
 	assertPodAnnotatedPending(t, client, pod)
 
+	// allow the call to succeed, this will stop further retry events from occurring
+	call.Return(nil)
+	// assert that the pod has been annotated before we proceed
+	assertPodAnnotated(t, client, pod)
+
 	// Assert expected calls actually made
 	fs.AssertExpectations(t)
 }