Merge branch '416611-bitbucket-server-importer-preserve-pr-mr-reviewers' into 'master'

BitBucket Server Importer - Preserve PR (MR) reviewers

https://gitlab.com/gitlab-org/gitlab/-/issues/416611

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/126729



Merged-by: Luke Duncalfe <lduncalfe@gitlab.com>
Approved-by: Luke Duncalfe <lduncalfe@gitlab.com>
Reviewed-by: George Koltsov <gkoltsov@gitlab.com>
Reviewed-by: Luke Duncalfe <lduncalfe@gitlab.com>
Reviewed-by: Bojan Marjanovic <bmarjanovic@gitlab.com>
Co-authored-by: bmarjanovic <bmarjanovic@gitlab.com>