Stop redirection loop with welcome during onboarding

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/183899



Merged-by: Doug Stull <dstull@gitlab.com>
Approved-by: Buck O'Leary <bucoleary@gitlab.com>
Approved-by: Aditya Tiwari <atiwari@gitlab.com>
Reviewed-by: Doug Stull <dstull@gitlab.com>