[solum] 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: I443a3c66e55657c2391f9688ee4b60c866aef4a3

deliverables/stein/python-solumclient.yaml

@@ -14,6 +14,10 @@ releases:
     projects:
       - repo: openstack/python-solumclient
         hash: 977717e756a6f4479480474777d2931c4860e7a6
+  - version: stein-eol
+    projects:
+      - repo: openstack/python-solumclient
+        hash: 9841840367f9c0d4495ea4af65096e8afe3be0cb
 branches:
   - location: 2.8.0
     name: stable/stein

deliverables/stein/solum-dashboard.yaml

@@ -14,6 +14,10 @@ releases:
     projects:
       - repo: openstack/solum-dashboard
         hash: 77c4c65f093b104748f6b60768ad0eb7c1d84586
+  - version: stein-eol
+    projects:
+      - repo: openstack/solum-dashboard
+        hash: f10dc8677d9353e1f225cdefd9844468f393a745
 branches:
   - location: 2.6.0
     name: stable/stein

deliverables/stein/solum.yaml

@@ -23,6 +23,10 @@ releases:
     projects:
       - repo: openstack/solum
         hash: c9d7760774ed7a749831592e426e14c6b5fba033
+  - version: stein-eol
+    projects:
+      - repo: openstack/solum
+        hash: e6a78919076229d90ff67650c8dac82fd390fde4
 branches:
   - location: 6.0.0.0rc1
     name: stable/stein