[magnum-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 the tag 1.6.0 hash which is compatible
for tempest ussuri-last and victoria-last.

[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: I0bdd7337e5da7f3934bb85e284758252ae8767cc

deliverables/ussuri/magnum-tempest-plugin.yaml

@@ -13,3 +13,7 @@ releases:
     projects:
       - repo: openstack/magnum-tempest-plugin
         hash: 0655f1a2cb6523945a96f9b596e13eee6f8f3bec
+  - version: ussuri-last
+    projects:
+      - repo: openstack/magnum-tempest-plugin
+        hash: 969753e8fd9c60134949a89f8d3ef95eb6ec9af6

deliverables/victoria/magnum-tempest-plugin.yaml

@@ -14,3 +14,7 @@ releases:
     projects:
       - repo: openstack/magnum-tempest-plugin
         hash: abe58fe334b0fd8d4806c0d8081cd74f4feafef3
+  - version: victoria-last
+    projects:
+      - repo: openstack/magnum-tempest-plugin
+        hash: 969753e8fd9c60134949a89f8d3ef95eb6ec9af6