Triggered releases broken in 11.2

An attempt to trigger the RC failed today: https://gitlab.com/gitlab-org/gitlab-ee/-/jobs/86094593

Looks to have been changed in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/6699

@balasankarc we should make the repo used in the trigger script configurable, so we can set it back to the main repo for the release job.