[mistral] 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: I0e914d6ed123fb6435e52d27dfbbeadc53514211

deliverables/zed/mistral-dashboard.yaml

@@ -16,6 +16,12 @@ releases:
       - repo: openstack/mistral-dashboard
         hash: 43903b7f3cd0fb7fe04da88517148539e865b9fc
     diff-start: 14.0.0
+  - version: zed-eom
+    projects:
+      - repo: openstack/mistral-dashboard
+        hash: 6c7a324351b4f5a82d2bf60dc2248f76a34820d5
 branches:
   - name: stable/zed
     location: 15.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom

deliverables/zed/mistral-extra.yaml

@@ -15,7 +15,13 @@ releases:
     projects:
       - repo: openstack/mistral-extra
         hash: 5f20dd26cc8bc60c3a1b64a942f4165ab57205c2
+  - version: zed-eom
+    projects:
+      - repo: openstack/mistral-extra
+        hash: 5f20dd26cc8bc60c3a1b64a942f4165ab57205c2
 branches:
   - name: stable/zed
     location: 12.0.1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/mistral-extra/zed.html

deliverables/zed/mistral-lib.yaml

@@ -11,7 +11,13 @@ releases:
     projects:
       - repo: openstack/mistral-lib
         hash: 18e4c693244254884178908d2126aa702496afa1
+  - version: zed-eom
+    projects:
+      - repo: openstack/mistral-lib
+        hash: 5045133e98f497281c93cf2317ace6cffcd8e1ba
 branches:
   - name: stable/zed
     location: 2.7.0
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/mistral-lib/zed.html

deliverables/zed/mistral.yaml

@@ -20,7 +20,13 @@ releases:
     projects:
       - repo: openstack/mistral
         hash: 0958cb23666122fee11e440a7596234b96bf9ddf
+  - version: zed-eom
+    projects:
+      - repo: openstack/mistral
+        hash: 0958cb23666122fee11e440a7596234b96bf9ddf
 branches:
   - name: stable/zed
     location: 15.0.0.0rc1
+  - name: unmaintained/zed
+    location: zed-eom
 release-notes: https://docs.openstack.org/releasenotes/mistral/zed.html

deliverables/zed/python-mistralclient.yaml

@@ -11,7 +11,14 @@ releases:
     projects:
       - repo: openstack/python-mistralclient
         hash: 8b9f313e3b9ddf3f057d2bf0a885070adcacb725
+  - version: zed-eom
+    projects:
+      - repo: openstack/python-mistralclient
+        hash: 8b9f313e3b9ddf3f057d2bf0a885070adcacb725
 branches:
   - name: stable/zed
     location: 4.5.0
-release-notes: https://docs.openstack.org/releasenotes/python-mistralclient/zed.html
+  - name: unmaintained/zed
+    location: zed-eom
+release-notes:
+  https://docs.openstack.org/releasenotes/python-mistralclient/zed.html