Merge branch 'add-instance-audit-event-for-enabling_admin_mode' into 'master'

Add instance audit event for enabling admin mode

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/104754



Merged-by: George Koltsov <gkoltsov@gitlab.com>
Approved-by: Smriti Garg <sgarg@gitlab.com>
Approved-by: George Koltsov <gkoltsov@gitlab.com>
Co-authored-by: Bogdan Denkovych <bdenkovych@gitlab.com>