Merge branch '419024-cells-iteration-2-convert-fk-between-users-and-members' into 'master'

Convert `members.user_id` to Loose Foreign Key

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/130083



Merged-by: Thong Kuah <tkuah@gitlab.com>
Approved-by: Thong Kuah <tkuah@gitlab.com>
Approved-by: Rutger Wessels <rwessels@gitlab.com>
Approved-by: Dylan Griffith <dyl.griffith@gmail.com>
Co-authored-by: Manoj M J <mmj@gitlab.com>