Makes QA jobs on staging to be manual
What does this MR do and why?
The post-migration jobs were removed on !1944 (merged), the removal of these jobs caused QA jobs on staging to be triggered right after tagging, see https://ops.gitlab.net/gitlab-org/release/tools/-/pipelines/1319870 as example.
Post-migrations jobs were manual because these migrations are now executed by the PDM, the fact that staging jobs depend on them caused this error.
Author Check-list
- [-] Has documentation been updated?