Add the "paralleltest" linter to the list of linters run with golangci-lint. That linter reports when tests don't call t.Parallel() to run subtests in parallel and when t.Parallel() is used incorrectly (e.g. without capturing the test case for loop variable). We have a lot of tests that can't currently be parallelized, so configure the linter to only check for incorrect usage, not missing t.Parallel() calls.