fix: use actor guard instead of commit message parsing in release workflow

Simpler self-trigger prevention: skip when actor is github-actions[bot]
(the auto-bump committer) instead of parsing commit messages.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: pofallon

.github/workflows/release.yaml

@@ -14,7 +14,7 @@ permissions:
 jobs:
   release:
     runs-on: ubuntu-latest
-    if: ${{ github.ref == 'refs/heads/main' && !contains(github.event.head_commit.message, 'chore: auto-bump feature versions') }}
+    if: github.ref == 'refs/heads/main' && github.actor != 'github-actions[bot]'
     steps:
       - uses: actions/checkout@v4
         with: