[designate] Transition Zed to Unmaintained

This branch reached the end of its official stable maintained period,
hence this patch transition stable/zed branch to Unmaintained. (For
details about Unmaintained state please see: [1][2])

The transitions is as follows:
- tip of the stable/zed branch is tagged with zed-eom tag
- unmaintained/zed branch will be cut from zed-eom tag
- stable/zed branch will be deleted

Note:
- there will no longer be official releases off of zed branch after this
  transition
- backports can be pushed to unmaintained/yoga branch
- openstack-unmaintained-core (or <project>-unmaintained-core groups if
  such exists) have the rights to merge patches

Important: please +1 if the team is ready for us to proceed with this
transition, or -1 if there are any final Zed stable release with
backports currently in flight that we should wait for. For the latter
case, please propose a final Zed stable release patch, and rebase this
patch on top of that, with the latest commit hash of stable/zed.

The transition deadline is May 2nd, 2024. [3]

[1] https://docs.openstack.org/project-team-guide/stable-branches.html#unmaintained
[2] https://governance.openstack.org/tc/resolutions/20230724-unmaintained-branches.html
[3] https://releases.openstack.org

Change-Id: I383f99c0504ccc4ef75f98e3cb1c47ed6158f9a9

deliverables/zed/designate-dashboard.yaml

@@ -16,7 +16,14 @@ releases:
       - repo: openstack/designate-dashboard
         hash: c2e55249e8af4f408d68bdc1381d9c720b29bdad
     diff-start: 14.0.0
+  - version: zed-eom
+    projects:
+      - repo: openstack/designate-dashboard
+        hash: c2a6a5e0d9fa1ec36c80136edb355e57918ad9d0
 branches:
   - name: stable/zed
     location: 15.0.0.0rc1
-release-notes: https://docs.openstack.org/releasenotes/designate-dashboard/zed.html
+  - name: unmaintained/zed
+    location: zed-eom
+release-notes:
+  https://docs.openstack.org/releasenotes/designate-dashboard/zed.html

deliverables/zed/designate.yaml

@@ -29,7 +29,13 @@ releases:
     projects:
       - repo: openstack/designate
         hash: d247267823034c5e656f74e91b50475aa54d3fa6
+  - version: zed-eom
+    projects:
+      - repo: openstack/designate
+        hash: d247267823034c5e656f74e91b50475aa54d3fa6
 branches:
   - name: stable/zed
     location: 15.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/designate/zed.html

deliverables/zed/python-designateclient.yaml

@@ -11,7 +11,14 @@ releases:
     projects:
       - repo: openstack/python-designateclient
         hash: 0d0d339cc6050122babb82d402c4d045d49c6629
+  - version: zed-eom
+    projects:
+      - repo: openstack/python-designateclient
+        hash: 92b924eb813512328969a9d12413ed0e4089f3b6
 branches:
   - name: stable/zed
     location: 5.0.0
-release-notes: https://docs.openstack.org/releasenotes/python-designateclient/zed.html
+  - name: unmaintained/zed
+    location: zed-eom
+release-notes:
+  https://docs.openstack.org/releasenotes/python-designateclient/zed.html