`ExpireBuildArtifactsWorker` is broken

https://sentry.gitlap.com/gitlab/gitlabcom/issues/20379/

PG::QueryCanceled: ERROR: canceling statement due to statement timeout : SELECT "ci_builds"."id" FROM "ci_builds" WHERE "ci_builds"."type" IN ('Ci::Build') AND (NOT (("ci_builds"."artifacts_file" = '' OR "ci_builds"."artifacts_file" IS NULL))) AND (artifacts_expire_at < '2017-12-12 10:50:02.714023')

Impact

• Prevents artifacts on GitLab.com from being properly auto-expired with artifacts: expire_in or default expiration settings. (As per: https://gitlab.com/gitlab-org/gitlab-ce/issues/51703)
• ..which causes the number of artifacts stored on GitLab.com to grow slowly
• And results in some increase to the amount of data needed to be synced between S3 and GCS (https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/4684)