Release sahara-image-elements RC1 for Antelope

This proposed a RC1 release for sahara-image-elements to get any merged changes
out prior to the RC1 deadline for Antelope going into effect.

If the team is ready to proceed, please leave a +1 to acknowledge this
release and we will process right away. If the team is working on any
final merges, leave a -1 with some detail on the status and update the
patch with the new commit hash to use when ready.

Patches with no response will be merged by early Friday, March 03.

$ git log --oneline --no-merges 17.0.0..ace7eda
ace7eda Drop lower-constraints.txt and its testing

Signed-off-by: Hervé Beraud <hberaud@redhat.com>
Change-Id: I15e9310e7456df87121cfe90622bb07e57a2530a

deliverables/antelope/sahara-image-elements.yaml

@@ -6,3 +6,11 @@ team: sahara
 type: other
 repository-settings:
   openstack/sahara-image-elements: {}
+releases:
+  - version: 18.0.0.0rc1
+    projects:
+      - repo: openstack/sahara-image-elements
+        hash: ace7eda8cdcc93592216954cc4a945988f2ab6d1
+branches:
+  - name: stable/2023.1
+    location: 18.0.0.0rc1