[senlin] Transition Xena to EM

This transition the stable/xena branch to extended maintenance.
Changes for bugfixes and things the team deems important are
still encouraged, but there will no longer be official releases
off of the branch after the transition.

Please +1 if the team is ready for us to proceed with this
transition, or -1 if there are any final backports currently in
flight that we should wait for. For the latter case, please
update the patch with the new commit hash after doing a final
release to get those changes out so we know to proceed with the
transition.

The transition deadline is April 20th, 2023.

Change-Id: Icdc5da7b9b7ec76dadd0a7ce3786ca918e4e4776

deliverables/xena/python-senlinclient.yaml

@@ -11,6 +11,10 @@ releases:
     projects:
       - repo: openstack/python-senlinclient
         hash: 9e21cdfd1aff56a6ab3b6a44286f7431d6cf53ad
+  - version: xena-em
+    projects:
+      - repo: openstack/python-senlinclient
+        hash: 9e21cdfd1aff56a6ab3b6a44286f7431d6cf53ad
 branches:
   - name: stable/xena
     location: 2.3.0

deliverables/xena/senlin-dashboard.yaml

@@ -15,6 +15,10 @@ releases:
       - repo: openstack/senlin-dashboard
         hash: fef54bb8bd95cfbe34679ba6e1c47a6842f59e6e
     diff-start: 3.0.0
+  - version: xena-em
+    projects:
+      - repo: openstack/senlin-dashboard
+        hash: fef54bb8bd95cfbe34679ba6e1c47a6842f59e6e
 branches:
   - name: stable/xena
     location: 4.0.0.0rc1

deliverables/xena/senlin.yaml

@@ -15,6 +15,10 @@ releases:
       - repo: openstack/senlin
         hash: 2216af7834c76fbaef49fc28d2febc8468589272
     diff-start: 11.0.0
+  - version: xena-em
+    projects:
+      - repo: openstack/senlin
+        hash: 2216af7834c76fbaef49fc28d2febc8468589272
 branches:
   - name: stable/xena
     location: 12.0.0.0rc1