Restore Gitaly server update and fix cached Git binary

What does this MR do and why?

This merge request restores !72366 (merged) (and reverts !72828 (merged)). In addition, it fixes the root cause for setup-test-env failing: the git binary path was not archived properly in the update-gitaly-binaries-cache CI job, as seen in https://gitlab.com/gitlab-org/gitlab/-/jobs/1703468890.

This prevented CI from using the right git version and Gitaly from starting.

In https://gitlab.com/gitlab-org/gitlab/-/jobs/1704292432, the cache increased from 129M to 192M:

$ ls -al gitaly*.zip
-rw-r--r--@ 1 stanhu  wheel  134568410 21 Oct 13:52 gitaly-cache.zip
-rw-r--r--  1 stanhu  wheel  192149252 21 Oct 17:05 gitaly-updated-cache.zip

Original cache:

original-cache.txt

Updated cache:

updated-cache.txt

Closes #343597 (closed)