[trove] 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: I9ca7187d55c73a11de85ab22ac6d99ebef0f1413

deliverables/zed/python-troveclient.yaml

@@ -15,7 +15,14 @@ releases:
     projects:
       - repo: openstack/python-troveclient
         hash: ad6544e8a5e754984e4ed9e29759d543933387d5
+  - version: zed-eom
+    projects:
+      - repo: openstack/python-troveclient
+        hash: 83f201e33a22c920c191c816feb9897de121e134
 branches:
   - name: stable/zed
     location: 8.0.0
-release-notes: https://docs.openstack.org/releasenotes/python-troveclient/zed.html
+  - name: unmaintained/zed
+    location: zed-eom
+release-notes:
+  https://docs.openstack.org/releasenotes/python-troveclient/zed.html

deliverables/zed/trove-dashboard.yaml

@@ -15,7 +15,13 @@ releases:
       - repo: openstack/trove-dashboard
         hash: cac088235db651a30c7e9ecf9b1a9551253c24e3
     diff-start: 18.0.0
+  - version: zed-eom
+    projects:
+      - repo: openstack/trove-dashboard
+        hash: 9b689c15d01ed04cc205cb083617dadc3ebf370f
 branches:
   - name: stable/zed
     location: 19.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/trove-dashboard/zed.html

deliverables/zed/trove.yaml

@@ -19,7 +19,13 @@ releases:
     projects:
       - repo: openstack/trove
         hash: c8579f514357f83b7b786f0389780cebdb453224
+  - version: zed-eom
+    projects:
+      - repo: openstack/trove
+        hash: 794e58e7406da324e185a16696750b07290ffa3e
 branches:
   - name: stable/zed
     location: 18.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/trove/zed.html