GitLab is used only for code review, issue tracking and project management. Canonical locations for source code are still https://gitweb.torproject.org/ https://git.torproject.org/ and git-rw.torproject.org.
deb.torproject.org is now also served via THS: http://sdscoq7snqtznauu.onion/
See #17937 (moved) and https://onion.torproject.org/
Please also add that to https://www.torproject.org/docs/debian.html.en