Skip live migration test on fs020

We don't have shared storage between compute nodes in CI.
This test used to get skipped on its own[1][2].

For some reason, `live_migration = false` is not set in tempestconf
in the latest jobs and this tests runs now and fails.

While we investigate and find cause what changed, Adding this test
manually on skip via skiplist.

[1] https://logserver.rdoproject.org/openstack-periodic-integration-main/opendev.org/openstack/tripleo-ci/master/periodic-tripleo-ci-centos-9-ovb-1ctlr_2comp-featureset020-master/d59ec78/logs/undercloud/var/log/tempest/tempest_run.log.txt.gz
~~~
tempest.scenario.test_network_advanced_server_ops.TestNetworkAdvancedServerOps.test_server_connectivity_live_migration ... SKIPPED: Live migration is not available.
~~~

[2] https://logserver.rdoproject.org/openstack-periodic-integration-main/opendev.org/openstack/tripleo-ci/master/periodic-tripleo-ci-centos-9-ovb-1ctlr_2comp-featureset020-master/d59ec78/logs/undercloud/var/log/tempest/tempestconf.log.txt.gz
~~~
2023-03-14 05:28:26.342 223102 DEBUG config_tempest.constants [-] Setting [compute-feature-enabled] live_migration = false set /usr/lib/python3.9/site-packages/config_tempest/tempest_conf.py:105
~~~

Related-Bug: #2011824
Change-Id: I1e7bb232e2f28749341db6d9e6881f8a28a2e06e

roles/validate-tempest/vars/tempest_skip.yml

@@ -1057,3 +1057,16 @@ known_failures:
           - 'osp'
     jobs:
       - periodic-tripleo-ci-rhel-9-ovb-3ctlr_1comp-featureset035-internal-rhos-17
+  - test: 'tempest.scenario.test_network_advanced_server_ops.TestNetworkAdvancedServerOps.test_server_connectivity_live_migration'
+    deployment:
+      - 'overcloud'
+    releases:
+      - name: 'master'
+        reason: 'We need shared storage between compute nodes for live migration'
+        lp: 'https://bugs.launchpad.net/tripleo/+bug/2011824/'
+      - name: 'zed'
+        reason: 'We need shared storage between compute nodes for live migration'
+        lp: 'https://bugs.launchpad.net/tripleo/+bug/2011824/'
+    jobs:
+      - periodic-tripleo-ci-centos-9-ovb-1ctlr_2comp-featureset020-master
+      - periodic-tripleo-ci-centos-9-ovb-1ctlr_2comp-featureset020-zed