Yak-shaving: Fix setup_indexes so it does less

We're nixing fixtures and we're at a point where we don't have to
assume there's anything in the db that needs to get indexed at
test setUp time.

This is pretty benign. It probably reduces the time involved a tiny
bit, but not a ton.

Mostly this nixes some complexity in test setup which will make
some tweaks I'm doing in the search overhaul less of a big deal.

r?