Depends on what you mean by migration.
We tried enabling CI/CD for our repo on Gitlab but my account was in some weird shadow-ban state where I couldn't see the CI/CD settings page that Gitlab's documentation was alluding to. Consequently, we sought Github.
We didn't have any vendor tie-in to Gitlab and our migration was just changing the Git remote repo.
└─ ▶ git remote -v
origin git@gitlab.com... (fetch)
origin git@gitlab.com... (push)
└─ ▶ git remote rm origin
└─ ▶ git remote add origin https://github.com/$USER/$REPO_NAME.git
└─ ▶ git push
With CI/CD, we now have vendor tie-in. Given that it took us a few hours and a few attempts to setup Github actions, and Gitlab is likely on the same order of magnitude of effort, the vendor tie-in doesn't seem to strong.
