[storlets] Transition Yoga to Unmaintained

With the new TC resolution the community replaces Extended Maintenance
with Unmaintained status [1].

So this patch transitions stable/yoga branch to Unmaintained as follows:
- tip of the stable/yoga branch is tagged with yoga-eom tag
- unmaintained/yoga branch will be cut from yoga-eom tag
- stable/yoga branch will be deleted

Some further notes:
- there will no longer be official releases off of yoga branch
- backports can be pushed against unmaintained/yoga branch
- openstack-unmaintained-core and <project>-unmaintained-core groups
  will have the rights to merge patches

For further details please read the resolution [1] & review and +1 this
patch if this is correct as soon as possible.

[1] https://governance.openstack.org/tc/resolutions/20230724-unmaintained-branches.html

Change-Id: I7ce01200376b791dbab111dd4e88d33a40b0606f

deliverables/yoga/storlets.yaml

@@ -15,7 +15,13 @@ releases:
       - repo: openstack/storlets
         hash: 1e79cc04452c30cd60bf704aaa8951f654cd189a
     diff-start: 8.0.0
+  - version: yoga-eom
+    projects:
+      - repo: openstack/storlets
+        hash: 9c91632cadfefa8a3bb69b7bca1dc06e029f853f
 branches:
   - name: stable/yoga
     location: 9.0.0.0rc1
+  - name: unmaintained/yoga
+    location: yoga-eom
 release-notes: https://docs.openstack.org/releasenotes/storlets/yoga.html