Your team follows a trunk-based workflow where the shared `main` branch is protected and continuously deployed by a GitLab CE pipeline. A merge commit that introduced a broken BGP template was already merged to `main` and deployed to production two hours ago. Several teammates have already pulled the latest `main` and started new work on top of it. You need to undo the effect of the broken merge on `main` while keeping the branch history intact and not disrupting your teammates' local clones. Which Git operation should you use?