[Tempest Plugins] Tag stein-last

Stein branch is in Extended Maintenance now[1]. All Tempest
plugins are branchless which means master version of Tempest
and its plugins is used to test the supported stable branches.

Once stable branch is moved to EM state then, Tempest and its
plugins compatible tag needs to be released so that we can
keep testing the EM stable branches with this tag once master
Tempest and its plugins are not compatible[2].

This tag will help for testing the stable/stein with single
compatible tag of Tempest and its plugins.

Tagging 'stein-last' as well as a new version also with same hash.
Documenting this new tag name here
- https://review.opendev.org/c/openstack/project-team-guide/+/769821

More detail on compatible version policy for Tempest and its
plugins is here
- https://docs.openstack.org/tempest/latest/tempest_and_plugins_compatible_version_policy.html

[1] https://releases.openstack.org/stein/index.html
[2] https://docs.openstack.org/tempest/latest/stable_branch_support_policy.html

Change-Id: I4f7e1e02954014403cab7ae502c588e2a21bce43

deliverables/stein/telemetry-tempest-plugin.yaml

@@ -13,3 +13,7 @@ releases:
       - hash: 7f0e315a78df17d981ed86ebddf87759cd97eedf
         repo: openstack/telemetry-tempest-plugin
     version: 0.3.0
+  - version: stein-last
+    projects:
+      - repo: openstack/telemetry-tempest-plugin
+        hash: 959fc69e492ed1d2297cce624c1efbf79e9f1b66

deliverables/wallaby/telemetry-tempest-plugin.yaml

@@ -9,3 +9,8 @@ repository-settings:
     tarball-base: telemetry_tempest_plugin
 team: Telemetry
 type: tempest-plugin
+releases:
+  - version: 1.2.0
+    projects:
+      - repo: openstack/telemetry-tempest-plugin
+        hash: 959fc69e492ed1d2297cce624c1efbf79e9f1b66