Remove loose_foreign_keys_clean_job_artifact_files feature flag
What does this MR do?
Removes the loose_foreign_keys_clean_job_artifact_files ops feature flag and makes the file-aware loose foreign key cleaner the permanent behaviour.
Tables that declare a cleaner_class (for example p_ci_job_artifacts) now always use it, so their backing files are cleaned up instead of being orphaned on storage by a bulk DELETE. The flag was default-off and has been rolled out, so the gating conditional and its YAML definition are removed, and the spec no longer needs a disabled-state context.
References
- Feature flag rollout: #604275
- Feature issue: #604201 (closed)