ipv6 single stack, e2e: skip tests that are not supported with no RA

Skip tests that are not supported until RA is introduced -
issue- #7184

Signed-off-by: Alona Kaplan <alkaplan@redhat.com>

tests/network/vmi_subdomain.go

@@ -51,6 +51,8 @@ var _ = SIGDescribe("Subdomain", func() {
 	)
 
 	BeforeEach(func() {
+		// Should be skipped as long as masquerade binding doesn't have dhcpv6 + ra (issue- https://github.com/kubevirt/kubevirt/issues/7184)
+		libnet.SkipWhenClusterNotSupportIpv4(virtClient)
 		var err error
 		virtClient, err = kubecli.GetKubevirtClient()
 		Expect(err).NotTo(HaveOccurred(), "Should successfully initialize an API client")