zoekt: update to sourcegraph/zoekt@f40c58e
Created by: bobheadxi
Updates zoekt dependency to https://github.com/sourcegraph/zoekt/commit/f40c58ef8631c357fb37311bd17e510a789d3a14
Also adds some output to ./dev/zoekt/update
to indicate that the go test
command is expected to not run any tests - was a bit worried when it came out with "no tests run"
Closes https://github.com/sourcegraph/sourcegraph/issues/28447