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.
Our pref changes from #3944 (closed) allow Tor Browser to get launched directly now. The original ticket to solve this was #4192 (closed). We're going to need to solve it differently now.