Release optimise GitHub import attachments feature

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/142257



Merged-by: Luke Duncalfe <lduncalfe@gitlab.com>
Approved-by: Joseph Wambua <jjoshua@gitlab.com>
Approved-by: Kerri Miller <kerrizor@kerrizor.com>
Co-authored-by: Luke Duncalfe <lduncalfe@eml.cc>