Add push trigger to release-publish for workflow registration

GitHub only registers workflow_dispatch workflows once they appear
on a branch via push. Adding a temporary push trigger for the branch.
All jobs are skipped on push (only run on workflow_dispatch).

Co-authored-by: Isaac

Author: pietern

.github/workflows/release-publish.yml

@@ -1,6 +1,11 @@
 name: release-publish
 
 on:
+  # Push trigger for testing on this branch. Remove before merging.
+  push:
+    branches:
+      - "split-release-workflows"
+
   workflow_dispatch:
     inputs:
       build_run_id:
@@ -23,7 +28,9 @@ env:
 jobs:
   # Always runs. Downloads artifacts from the build run and verifies them.
   # In non-dry-run mode, also creates the GitHub release.
+  # Skipped on push trigger (used only to register the workflow with GitHub).
   prepare-release:
+    if: ${{ github.event_name == 'workflow_dispatch' }}
     runs-on:
       group: databricks-deco-testing-runner-group
       labels: ubuntu-latest-deco