[Telemetry] 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: I417ddda72bbb08775cfe616f81db6664897f5299

deliverables/zed/aodh.yaml

@@ -15,7 +15,13 @@ releases:
       - repo: openstack/aodh
         hash: 1ead679b313fce766448fea73d424cd1c11b57c7
     diff-start: 14.0.0
+  - version: zed-eom
+    projects:
+      - repo: openstack/aodh
+        hash: 6c23448f0c4a2a9a52344aa935a1b28020e6e70d
 branches:
   - name: stable/zed
     location: 15.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/aodh/zed.html

deliverables/zed/ceilometer.yaml

@@ -19,7 +19,13 @@ releases:
     projects:
       - repo: openstack/ceilometer
         hash: 5968c822bebbaa47ef71d56abb4b7c2bd41fa7b9
+  - version: zed-eom
+    projects:
+      - repo: openstack/ceilometer
+        hash: a0e2230e3b9dc0f741bb71060950260c4c33148b
 branches:
   - name: stable/zed
     location: 19.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/ceilometer/zed.html

deliverables/zed/ceilometermiddleware.yaml

@@ -11,7 +11,14 @@ releases:
     projects:
       - repo: openstack/ceilometermiddleware
         hash: 5c01e19b3846c1a0308d68d428c0cee440172dae
+  - version: zed-eom
+    projects:
+      - repo: openstack/ceilometermiddleware
+        hash: 610ca284cced47c6f324a3e8b176d2648e3a7252
 branches:
   - name: stable/zed
     location: 3.0.0
-release-notes: https://docs.openstack.org/releasenotes/ceilometermiddleware/zed.html
+  - name: unmaintained/zed
+    location: zed-eom
+release-notes:
+  https://docs.openstack.org/releasenotes/ceilometermiddleware/zed.html

deliverables/zed/python-aodhclient.yaml

@@ -12,6 +12,12 @@ releases:
     projects:
       - repo: openstack/python-aodhclient
         hash: a1f47383a466da62f6722b3ef675e1adb92360a4
+  - version: zed-eom
+    projects:
+      - repo: openstack/python-aodhclient
+        hash: fe17cce7c1c14e03983e12d7a1973808ff668970
 branches:
   - name: stable/zed
     location: 3.0.0
+  - name: unmaintained/zed
+    location: zed-eom