Merge branch 'id-remove-repack_after_shard_migration' into 'master'

Remove repack_after_shard_migration feature flag

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/111961



Merged-by: Vitali Tatarintev <vtatarintev@gitlab.com>
Approved-by: Vitali Tatarintev <vtatarintev@gitlab.com>
Co-authored-by: Igor Drozdov <idrozdov@gitlab.com>