[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: If5360db5adcefc8bce0b38c21172e725e0a5d3f1

deliverables/stein/designate-tempest-plugin.yaml

@@ -12,3 +12,7 @@ releases:
     projects:
       - repo: openstack/designate-tempest-plugin
         hash: c1708fc0c878ea3fa544454c7e96c58581478853
+  - version: stein-last
+    projects:
+      - repo: openstack/designate-tempest-plugin
+        hash: 5da3047851aae36f09e0b52f79523426fec6a104

deliverables/wallaby/designate-tempest-plugin.yaml

@@ -8,3 +8,8 @@ repository-settings:
   openstack/designate-tempest-plugin: {}
 team: designate
 type: tempest-plugin
+releases:
+  - version: 0.10.0
+    projects:
+      - repo: openstack/designate-tempest-plugin
+        hash: 5da3047851aae36f09e0b52f79523426fec6a104