[magnum] Transition Queens to End of Life

This transition the Queens branch to End of Life. The last patch of the
branch will be tagged with queens-eol tag. The stable/queens branch
cannot be used anymore and will be deleted if this patch merges.

This is needed as stable/queens is not actively maintained in the recent
period and 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/queens is deleted, and 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.

Change-Id: If095d77e288a1faa97d2b6eba01559ad1973e625

deliverables/queens/python-magnumclient.yaml

@@ -21,6 +21,10 @@ releases:
     projects:
       - repo: openstack/python-magnumclient
         hash: 40327b75edcab608e9c9d9ac0993855de088926b
+  - version: queens-eol
+    projects:
+      - repo: openstack/python-magnumclient
+        hash: 436a1910e7cbf96e7bf4fded636bf68674bf292e
 branches:
   - location: 2.8.0
     name: stable/queens