- Add missing checkout step to fix 'fatal: not a git repository' error
- Add required permissions (metadata: read, actions: read) for auto-merge
- Improve error handling with GitHub API and graceful fallback behavior
- Add informative comments to PRs when auto-merge fails due to permissions
- Ensure workflow doesn't fail when auto-merge permissions are insufficient

Fixes dependabot auto-merge workflow failures and provides better user experience.

- Add repository check to prevent workflow from running on forks
- Fixes unwanted failure notifications on personal forks
- Ensures workflow only runs on openshift/backplane-cli where intended

- Use environment variable reference instead of direct secret interpolation
- Add explicit comments about automatic token masking
- Add silent flag to curl commands to reduce log verbosity
- Addresses security concerns about token exposure in public repo logs

Co-authored-by: feichashao

- Remove X-GitHub-Api-Version header to avoid version binding
- GitHub REST API is backward compatible and version header is optional
- Simplifies API calls and reduces maintenance overhead