Drop helix from the gitolite maintainer role
The infrastructure wiki page says that the git-rw admins are erinn, nickm, sebastian, weasel: https://trac.torproject.org/projects/tor/wiki/org/operations/Infrastructure
I hear irl has become a new git-rw admin (yay), and also weasel has moved himself to a backup (emergency rescue) role.
We should disable erinn's gitolite admin bits for now, on the "information hygiene" principle, since she hasn't been doing that role for a good while now and we have enough people who are. She can always resume doing it if she becomes more active again.
And when we've done these things we should update the git-rw box in the infrastructure wiki page.