Prepare 15.7.9 release for gitlab-jh
Release issue: https://jihulab.com/gitlab-cn/release/tasks/-/issues/54
Summary
This MR prepares 15-7-stable-jh
for 15.7.9
.
Automated cherry-picking
Merge requests labeled Pick into 15.7 should be automatically picked into this MR.
Manual intervention
If merge requests cannot be picked automatically they have to be created
manually targeting 15-7-stable-jh-patch-9
.
See also Patch Releases documentation.