[ovn][ipv6] Add some more tests to skiplist

This is same to already skipped test in [1][2].

[1] https://review.opendev.org/c/openstack/neutron/+/874112
[2] https://review.opendev.org/c/openstack/neutron/+/885074

Related-Bug: #2007166
Change-Id: Ie93833538056edeb4da4c38e5139390f1c124724
(cherry picked from commit add2a6e)
Conflicts:
	zuul.d/tempest-singlenode.yaml

Author: karelyatin

zuul.d/tempest-singlenode.yaml

@@ -568,4 +568,6 @@
       # of ovn https://bugs.launchpad.net/neutron/+bug/2007166
       tempest_exclude_regex: "\
           (test_update_delete_extra_route)|\
-          (test_update_router_admin_state)"
+          (test_update_router_admin_state)|\
+          (test_dhcp_stateful_router)|\
+          (TestSecurityGroupsBasicOps)"