test,networksegmentation: Wait for CUDN object be gone

On CUDN cleanup is inconsistent as we see some flaky tests due to CUDN
"already exist" errors, implying object are not actually deleted.

Wait for CUDN object be gone when deleted.

Signed-off-by: Or Mergi <ormergi@redhat.com>

test/extended/networking/network_segmentation.go

@@ -560,6 +560,10 @@ var _ = Describe("[sig-network][OCPFeatureGate:NetworkSegmentation][Feature:User
 					Expect(err).NotTo(HaveOccurred())
 					_, err = e2ekubectl.RunKubectl("", "delete", "clusteruserdefinednetwork", c.name)
 					Expect(err).NotTo(HaveOccurred())
+					Eventually(func() bool {
+						_, err := e2ekubectl.RunKubectl("", "get", "clusteruserdefinednetwork", c.name)
+						return kerrors.IsNotFound(err)
+					}, 1*time.Minute, 3*time.Second).Should(BeTrueBecause("ClusterUserDefinedNetwork %q should be gone", c.name))
 				})
 				Expect(waitForClusterUserDefinedNetworkReady(c.name, 5*time.Second)).To(Succeed())
 				return err
@@ -728,6 +732,10 @@ var _ = Describe("[sig-network][OCPFeatureGate:NetworkSegmentation][Feature:User
 				DeferCleanup(func() error {
 					cleanup()
 					_, _ = e2ekubectl.RunKubectl("", "delete", clusterUserDefinedNetworkResource, testClusterUdnName)
+					Eventually(func() bool {
+						_, err := e2ekubectl.RunKubectl("", "get", clusterUserDefinedNetworkResource, testClusterUdnName)
+						return kerrors.IsNotFound(err)
+					}, 1*time.Minute, 3*time.Second).Should(BeTrueBecause("ClusterUserDefinedNetwork %q should be gone", testClusterUdnName))
 					return nil
 				})
 				Expect(err).NotTo(HaveOccurred())
@@ -942,6 +950,10 @@ var _ = Describe("[sig-network][OCPFeatureGate:NetworkSegmentation][Feature:User
 			DeferCleanup(func() error {
 				cleanup()
 				_, _ = e2ekubectl.RunKubectl("", "delete", "clusteruserdefinednetwork", cudnName)
+				Eventually(func() bool {
+					_, err := e2ekubectl.RunKubectl("", "get", "clusteruserdefinednetwork", cudnName)
+					return kerrors.IsNotFound(err)
+				}, 1*time.Minute, 3*time.Second).Should(BeTrueBecause("ClusterUserDefinedNetwork %q should be gone", cudnName))
 				return nil
 			})