- ci_builds.artifacts_expire_at are copied to
  ci_job_artifacts.expire_at with incorrect timestamps when the
  database timezone is NOT utc

- ci_builds.artifacts_expire_at is `timestamp without time zone` and
  ci_job_artifacts.expire_at is `timestamp with time zone` on
  postgresql

- Tests fail locally for `rspec
  ./spec/lib/gitlab/import_export/import_export_spec.rb` without this
  change