Cleanup pod in MatchContainerOutput

MatchContainerOutput always creates a pod and does not cleanup. We need
to fix this to be better at re-trying the scenarios.

When there is an error say in the first attempt of ExpectNoErrorWithRetries
(for example in "Pods should contain environment variables for services" test)
the retries logic calls MatchContainerOutput another time and the
podClient.create fails correctly since the pod was not cleaned up the
first time MatchContainerOutput was called.

Fixes #35089

test/e2e/framework/util.go

@@ -2163,6 +2163,10 @@ func (f *Framework) MatchContainerOutput(
 	ns := f.Namespace.Name
 
 	createdPod := podClient.Create(pod)
+	defer func() {
+		By("delete the pod")
+		podClient.DeleteSync(createdPod.Name, &api.DeleteOptions{}, podNoLongerRunningTimeout)
+	}()
 
 	// Wait for client pod to complete.
 	if err := WaitForPodSuccessInNamespace(f.ClientSet, createdPod.Name, ns); err != nil {