Update Gitaly version to fix setup-test-env

https://gitlab.com/gitlab-org/gitaly/-/merge_requests/2490 fixes a
problem where the Nokogiri `bundle install` would fail because the
`PATH` environment was changed to run the a script that blocked `git`
executions from the default `PATH`. The problem only occurred if the Gem
cache were expired.

Closes https://gitlab.com/gitlab-org/gitlab-foss/-/issues/78945

GITALY_SERVER_VERSION

-0fe0cfaccc979592610cbf65807f19b307957750
+a7f84c7c8ea135881fd2cc6c7f48fdc487b125fb