Cosmetic update to 12.8.5.
This update does not include any change compared to 12.8.3 but is required to show a green light for the update in the admin interface.
Changes that were part of the upgrade to 12.8.3 (changelog was not existing on commit date):
https://about.gitlab.com/releases/2020/03/09/gitlab-12-8-5-released/

The information on the gitlab changelog is so not 100% correct.