Search backend: use client logger where applicable
Created by: camdencheek
This takes the logger from RuntimeClients
and uses it instead of log15 where applicable. Part of reimplementing https://github.com/sourcegraph/sourcegraph/pull/36457 incrementally and so it fits search idioms.
Stacked on https://github.com/sourcegraph/sourcegraph/pull/38129
Following this PR, there are only 5 uses of log15
in internal/search
. I'll probably leave it here for now because the other uses are more entrenched.
This also re-enables the log15 lint that I disabled to get this series of PRs through.
Test plan
Unit tests