This validation code has 2 bugs, the main one being that it is wrong and
is refusing perfectly valid codes. Let's remove this until we come up
with a valid check.
This reverts commit cd8b546205.
Fixes: cd8b546205 ("bin/ci: Add GitLab basic token validation")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27312>