[manila] 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: I382b38783c228ac09ee7b4f46aa28c0baf74950c

deliverables/zed/manila-ui.yaml

@@ -16,7 +16,13 @@ releases:
       - repo: openstack/manila-ui
         hash: 93070d335bd2d3cce1f703fc53e3f97b8555d1a2
     diff-start: 7.0.0
+  - version: zed-eom
+    projects:
+      - repo: openstack/manila-ui
+        hash: 18bdfe774cfbddb2f997b405eb5172e44f014d4a
 branches:
   - name: stable/zed
     location: 8.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/manila-ui/zed.html

deliverables/zed/manila.yaml

@@ -57,7 +57,13 @@ releases:
     projects:
       - repo: openstack/manila
         hash: 9b2916254cded2266a2594be1748fa4d88de5e9b
+  - version: zed-eom
+    projects:
+      - repo: openstack/manila
+        hash: 9b2916254cded2266a2594be1748fa4d88de5e9b
 branches:
   - name: stable/zed
     location: 15.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/manila/zed.html

deliverables/zed/python-manilaclient.yaml

@@ -31,7 +31,14 @@ releases:
     projects:
       - repo: openstack/python-manilaclient
         hash: 0214e59a3fd162be5e61db1a1991fee8854d83b7
+  - version: zed-eom
+    projects:
+      - repo: openstack/python-manilaclient
+        hash: 4eee3bf60b5285f247b6b3e3a415b21539b582d3
 branches:
   - name: stable/zed
     location: 4.1.0
-release-notes: https://docs.openstack.org/releasenotes/python-manilaclient/zed.html
+  - name: unmaintained/zed
+    location: zed-eom
+release-notes:
+  https://docs.openstack.org/releasenotes/python-manilaclient/zed.html