sql: skip test with race
sql: skip test with race

This was previously skipped, but the skip was removed last commit
because the linked issue in lib/pq was fixed. But there are some more
underlying races, so we must ignore it again.

See: https://github.com/lib/pq/issues/558

Closes #12934

maxlang/cockroach,maxlang/cockroach,paperstreet/cockroach,paperstreet/cockroach,maxlang/cockroach,paperstreet/cockroach,maxlang/cockroach,maxlang/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,maxlang/cockroach,maxlang/cockroach,maxlang/cockroach,paperstreet/cockroach