[congress] Transition Stein to End of Life

As announced on mailing list [1], this patch transitions the Stein
branch to End of Life. The last patch of the branch will be tagged with
stein-eol tag. stable/stein branch cannot be used anymore and will be
deleted if this patch merges.

This is needed as stable/stein is not actively maintained in recent
period, thus gates are mostly broken due to job failures. Besides,
by removing these branches, infra resources will be freed up, too.

Please try to identify any zuul job, that is defined outside of the
repositories in this patch (for example in openstack-zuul-jobs, etc.)
and won't be used anymore if stable/stein is deleted. Propose a job
removal patch for them.

Please +1 if the team is ready for us to proceed with this transition,
or -1 if there are still some activity on the branch and the team wants
to continue to maintain it.

[1] https://lists.openstack.org/pipermail/openstack-discuss/2023-September/034965.html

Change-Id: I096db543219fe62e2e23ddc5e2280e2279dd206a

deliverables/stein/congress-dashboard.yaml

@@ -20,7 +20,12 @@ releases:
     projects:
       - repo: openstack/congress-dashboard
         hash: e5c562c7b3cab096d6b46d353a836bf71044917a
+  - version: stein-eol
+    projects:
+      - repo: openstack/congress-dashboard
+        hash: 882c2db1c6cea2d6eb9651102b31e8baee56917d
 branches:
   - location: 4.0.0.0rc1
     name: stable/stein
-release-notes: https://docs.openstack.org/releasenotes/congress-dashboard/stein.html
+release-notes: 
+  https://docs.openstack.org/releasenotes/congress-dashboard/stein.html

deliverables/stein/congress.yaml

@@ -24,6 +24,10 @@ releases:
     projects:
       - repo: openstack/congress
         hash: 4977fe3dacbf4de25e8568141d9bdbf7363a5288
+  - version: stein-eol
+    projects:
+      - repo: openstack/congress
+        hash: b565c87d0224abb76d3710a4238df433f75ffbf3
 branches:
   - location: 9.0.0.0rc1
     name: stable/stein

deliverables/stein/python-congressclient.yaml

@@ -13,6 +13,10 @@ releases:
     projects:
       - repo: openstack/python-congressclient
         hash: b7044328112bdeda1b7bc36da1e5c8f863b3c72a
+  - version: stein-eol
+    projects:
+      - repo: openstack/python-congressclient
+        hash: ab404635582e986377d539091eb13d6c7fc3577f
 repository-settings:
   openstack/python-congressclient: {}
 branches: