Gitlab doesn't mandate anything. Also, even if your CI pipeline does use Docker, it doesn't matter if "you don't use Docker" _as a team_. Your pipeline may name

Gitlab doesn't mandate anything. Also, even if your CI pipeline does use Docker, it doesn't matter if "you don't use Docker" _as a team_. Your pipeline may name an image, and that's it. That's way different than maintaining your own Dockerfiles and images.