[skyline] 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: I35ddff9a77901be180b2134acfa8a1ff6738e276

deliverables/zed/skyline-apiserver.yaml

@@ -33,7 +33,13 @@ releases:
     projects:
       - repo: openstack/skyline-apiserver
         hash: 8bf02f88963ee25bfb1c99083c2cd618de6819e5
+  - version: zed-eom
+    projects:
+      - repo: openstack/skyline-apiserver
+        hash: 8bf02f88963ee25bfb1c99083c2cd618de6819e5
 branches:
   - name: stable/zed
     location: 1.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/skyline-apiserver/zed.html

deliverables/zed/skyline-console.yaml

@@ -57,7 +57,13 @@ releases:
     projects:
       - repo: openstack/skyline-console
         hash: dd15b360ecb5ff3d0d7bfb209e4b0b3013c4ef53
+  - version: zed-eom
+    projects:
+      - repo: openstack/skyline-console
+        hash: dd15b360ecb5ff3d0d7bfb209e4b0b3013c4ef53
 branches:
   - name: stable/zed
     location: 1.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/skyline-console/zed.html