[barbican-tempest-plugin] Tag xena-last

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

Once any stable branch is moved to EM state then, Tempest and
its plugins compatible tag[2] needs to be released so that we can
keep testing the EM stable branches with that tag once master
Tempest and its plugins are not compatible[3].

Tagging 'xena-last' as well as a new version also with same hash.

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

Change-Id: Ib09542fe62875045db2c332d83b1089f0a1bef36

deliverables/bobcat/barbican-tempest-plugin.yaml

@@ -9,3 +9,8 @@ repository-settings:
     tarball-base: barbican_tempest_plugin
 team: barbican
 type: tempest-plugin
+releases:
+  - version: 2.1.0
+    projects:
+      - repo: openstack/barbican-tempest-plugin
+        hash: e765946be16235dafa82809183a4b9e2fa14e078

deliverables/xena/barbican-tempest-plugin.yaml

@@ -17,4 +17,8 @@ releases:
     projects:
       - repo: openstack/barbican-tempest-plugin
         hash: 8400a79a94cfa2247dd259414e12b65918178e1e
+  - version: xena-last
+    projects:
+      - repo: openstack/barbican-tempest-plugin
+        hash: e765946be16235dafa82809183a4b9e2fa14e078
 type: tempest-plugin