[neutron-tempest-plugin] Tag ussuri-last & victoria-last

Ussuri and Victoria branches are in Extended Maintenance[1].
Once any stable branch is moved to EM state then, Tempest and
its plugins needs to be released[2] so that we have the compatible
tags to test the EM stable branches[3].

We taged ussuri-last & victoria-last for tempest[4] but forgot to do
it for the tempest plugins. Using 1.6.0 tag which is what is used for
neutron ussuir and victoria testing.

- 3ff8300038/zuul.d/ussuri_jobs.yaml (L9)
- 3ff8300038/zuul.d/victoria_jobs.yaml (L8)

[1] https://docs.openstack.org/tempest/latest/stable_branch_support_policy.html
[2] https://docs.openstack.org/tempest/latest/tempest_and_plugins_compatible_version_policy.html
[3] https://review.opendev.org/c/openstack/releases/+/843039

Change-Id: Ie7f0b626d8d4a23490a2b244d7c5ba5d5b3bdca4

deliverables/ussuri/neutron-tempest-plugin.yaml

@@ -29,3 +29,7 @@ releases:
     projects:
       - repo: openstack/neutron-tempest-plugin
         hash: 5719f992d146505eb593d1fd68d02e4945e2e07f
+  - version: ussuri-last
+    projects:
+      - repo: openstack/neutron-tempest-plugin
+        hash: c55bd059edb990454eba01f512fc40d09d02db26

deliverables/victoria/neutron-tempest-plugin.yaml

@@ -14,3 +14,7 @@ releases:
     projects:
       - repo: openstack/neutron-tempest-plugin
         hash: 7d5988b29b6eb27b2dc954ea287c85bfa2ec67c4
+  - version: victoria-last
+    projects:
+      - repo: openstack/neutron-tempest-plugin
+        hash: c55bd059edb990454eba01f512fc40d09d02db26