I'm curious what you'd expect CI to do regarding running backups. Starting in 9.1, you can run CI pipelines on a schedule, so you could have nightly backups triggered by a CI job, but I would think there are better ways to handle that.

Now if you're following infrastructure-as-code, and your backup and other configurations are saved in version control, then of course GitLab supports that, but that's not explicitly GitLab CI.

GitLab CI does support deployment histories, easy rollback, etc.