[swift] 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: I95752dbfc8a1c5b005c39b22ce00b9dd7881c06d

deliverables/stein/python-swiftclient.yaml

@@ -19,7 +19,12 @@ releases:
     projects:
       - repo: openstack/python-swiftclient
         hash: c2ba4df5e229549447658469cded8f31e2822bf5
+  - version: stein-eol
+    projects:
+      - repo: openstack/python-swiftclient
+        hash: c2ba4df5e229549447658469cded8f31e2822bf5
 branches:
   - location: 3.7.0
     name: stable/stein
-release-notes: https://docs.openstack.org/releasenotes/python-swiftclient/stein.html
+release-notes: 
+  https://docs.openstack.org/releasenotes/python-swiftclient/stein.html

deliverables/stein/swift.yaml

@@ -28,6 +28,10 @@ releases:
     projects:
       - repo: openstack/swift
         hash: 522823548a61745b95f079ed092ba80d57265b1c
+  - version: stein-eol
+    projects:
+      - repo: openstack/swift
+        hash: 12e54391861e7d182d58f89fb88b027e65842640
 cycle-highlights:
   - Numerous improvements to the S3 API compatibility layer.
   - Several fixes and improvements for the data-encryption middleware,