[glance] 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: Ic31eaeb2cb08f5b929693fef31f9da3611defe5c

deliverables/xena/glance-store.yaml

@@ -19,6 +19,10 @@ releases:
     projects:
       - repo: openstack/glance_store
         hash: a4ba0c4fded13190f9161acedf6240f025718a77
+  - version: xena-em
+    projects:
+      - repo: openstack/glance_store
+        hash: a4ba0c4fded13190f9161acedf6240f025718a77
 branches:
   - name: stable/xena
     location: 2.7.0

deliverables/xena/glance.yaml

@@ -36,6 +36,10 @@ releases:
     projects:
       - repo: openstack/glance
         hash: 4fc2ea4a85bbca25fae84a7506bf78f08d6485bf
+  - version: xena-em
+    projects:
+      - repo: openstack/glance
+        hash: 4fc2ea4a85bbca25fae84a7506bf78f08d6485bf
 branches:
   - name: stable/xena
     location: 23.0.0.0rc1

deliverables/xena/python-glanceclient.yaml

@@ -15,6 +15,10 @@ releases:
     projects:
       - repo: openstack/python-glanceclient
         hash: 74a55bd2fc0bd5fcab75d6be197eff0882470da7
+  - version: xena-em
+    projects:
+      - repo: openstack/python-glanceclient
+        hash: 74a55bd2fc0bd5fcab75d6be197eff0882470da7
 branches:
   - name: stable/xena
     location: 3.5.0