Move the bwauths to be relays, so they won't get throttled
To finish #9368 (moved), we should make the Tors that the bwauths use be relays.
This one could be harder than it should be, since from #8688 (moved) we learned that we actually have no idea who runs the bwauths or which ones are hooked up to which dir auths.
That said: from looking at the current votes, I see that moria1, gabelmoo, turtles show Measured lines. I think maatuska might too, but it's down.
So that's four people, and it should be manageable.