Vulnerability::IssueLink migration
The root cause behind #223770 is a [data integrity problem](https://gitlab.com/gitlab-org/gitlab/-/issues/223770#note_366616094).
After a [failed attempt](https://gitlab.com/gitlab-org/gitlab/-/issues/223770#note_391815993) to resolve the issue without a data migration, we decided to perform the database migration as the safest approach.
epic