GitLab Pages has added a feature to do proper HTTP redirects, which
are genreally better than the HTML redirects we currently use.
Unfortunately, it doesn't support redirecting to other domains, all
paths must start with a slash. So there's sadly *one* redirect this
doesn't work for. So let's leave that one using a HTML redirect, and
use HTTP redirects when we can.
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14369>