Draft: Reapply "Add CI jobs with Gitaly transactions"
What does this MR do and why?
Reapply "Add CI jobs with Gitaly transactions"
This reverts commit 74e70a09.
While reapplying the commit, we are configuring the jobs to only run during maintenance pipelines to reduce the load on the CI workers.
Reapplies the changes from !144582 (merged) that were reverted in Revert "Add CI jobs with Gitaly transactions" (!153450 - merged)