Merge branch 'sk/404080-add-migration' into 'master'

Add migration to re-sync scan result policies for namespaces

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/116608



Merged-by: Adam Hegyi <ahegyi@gitlab.com>
Approved-by: Dominic Bauer <dbauer@gitlab.com>
Approved-by: Adam Hegyi <ahegyi@gitlab.com>
Reviewed-by: Adam Hegyi <ahegyi@gitlab.com>
Co-authored-by: Sashi Kumar <skumar@gitlab.com>