Xena: update Github Actions workflows

Author: markgoddard

.github/workflows/container-image-build.yml

@@ -35,7 +35,7 @@ jobs:
         uses: actions/checkout@v3
         with:
           repository: stackhpc/kayobe
-          ref: refs/heads/stackhpc/wallaby
+          ref: refs/heads/stackhpc/xena
           path: src/kayobe
 
       # FIXME: Failed in kolla-ansible : Ensure the latest version of pip is installed

.github/workflows/promote.yml

@@ -3,9 +3,8 @@ name: Promote package repositories
 on:
   push:
     branches:
-      # NOTE(mgoddard): Keep this list tightly controlled, since we only want
-      # to promote from release branches.
-      - stackhpc/wallaby
+      # NOTE(mgoddard): Reference only the current release branch here.
+      - stackhpc/xena
 jobs:
   promote:
     name: Trigger package repository promotion