Fix issue #5080: [Bug]: lint-fix.yml github action doesn't work on a branch not from this repo

[openhands-agent]

This pull request fixes #5080.

The issue has been successfully resolved. The original problem was that the GitHub Action was failing when trying to check out code from PRs originating from forks because it couldn't properly access the source repository. The fix implemented adds the correct repository parameter to the actions/checkout action, specifically using ${{ github.event.pull_request.head.repo.full_name }} which dynamically references the source repository of the PR.

This solution:

1. Addresses the core issue by ensuring the action can access code from forked repositories
2. Still maintains compatibility with PRs from the same repository
3. Fixes the specific error where the action couldn't find the branch checkout-a-non-main-branch-option

The PR reviewer should know that this is a straightforward configuration change to the GitHub Actions workflow that improves the robustness of the lint-fix action by making it work with PRs from both internal branches and external forks. No code changes were required, only workflow configuration updates.

Automatic fix generated by OpenHands 🙌

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To run this PR locally, use the following command:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:a8ab4bf-nikolaik   --name openhands-app-a8ab4bf   docker.all-hands.dev/all-hands-ai/openhands:a8ab4bf

[tobitege]

This shouldn't run on forks. People have their forks' own potential clones and this may interfere unwantedly with their work.
In addition, this mostly won't be able to commit anyways as security wouldn't be set up for this cross-repo access.

[neubig]

Thanks for the comment @tobitege , but could you elaborate? This will only be run if we set the lint-fix label, and it can only be pushed to their forks' branch if they check the box saying maintainers can push to their branch. So I think the danger of allowing this is probably minimal?

[tobitege]

Thanks for the comment @tobitege , but could you elaborate? This will only be run if we set the lint-fix label, and it can only be pushed to their forks' branch if they check the box saying maintainers can push to their branch. So I think the danger of allowing this is probably minimal?

I just don't like this personally, and it's another thing that isn't obvious to a user/contributor and needs documentation.

[neubig]

OK, thanks for approving anyway @tobitege !