[winstackers] 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: Ic4212234047e169a2d26b0712fa9887d1635d728

deliverables/xena/compute-hyperv.yaml

@@ -15,6 +15,10 @@ releases:
       - repo: openstack/compute-hyperv
         hash: 1971a6719e89eac9addd4048312c028a2bfbcd03
     diff-start: 12.0.0
+  - version: xena-em
+    projects:
+      - repo: openstack/compute-hyperv
+        hash: 1971a6719e89eac9addd4048312c028a2bfbcd03
 branches:
   - name: stable/xena
     location: 13.0.0.0rc1

deliverables/xena/networking-hyperv.yaml

@@ -16,6 +16,10 @@ releases:
       - repo: openstack/networking-hyperv
         hash: 2329562d274b953851603f09f59b140b21a898b4
     diff-start: 10.0.0
+  - version: xena-em
+    projects:
+      - repo: openstack/networking-hyperv
+        hash: 2329562d274b953851603f09f59b140b21a898b4
 branches:
   - name: stable/xena
     location: 11.0.0.0rc1

deliverables/xena/os-win.yaml

@@ -11,6 +11,10 @@ releases:
     projects:
       - repo: openstack/os-win
         hash: d571260d41bfe309412570785665a9afd8d8eef2
+  - version: xena-em
+    projects:
+      - repo: openstack/os-win
+        hash: d571260d41bfe309412570785665a9afd8d8eef2
 branches:
   - name: stable/xena
     location: 5.5.0