Swap 1.x backport branch name for automation compatibility

Author: dfreeman

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ on:
     # filtering branches here prevents duplicate builds from pull_request and push
     branches:
       - master
-      - 'v*'
+      - 'release-*'
     # always run CI for tags
     tags:
       - '*'