ci: disable draft PRs for publish-to-bcr workflow (#576)

## Summary
- Disable draft PRs for the publish-to-bcr workflow since repos hosted
under bazel-contrib using the shared bot token should not create draft
PRs
- Maintainers listed in metadata.json will approve the non-draft PRs
instead

## Test plan
- [ ] Verify workflow runs successfully on next release

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: cgrindel

.github/workflows/publish_to_bcr.yml

@@ -21,5 +21,6 @@ jobs:
       author_name: Chuck Grindel
       author_email: chuck.grindel@gmail.com
       attest: false
+      draft: false
     secrets:
       publish_token: ${{ secrets.BCR_PUBLISH_TOKEN }}