Update GitLab Workhorse to v8.34.0

This fixes a ZIP download issue with some S3 providers
(https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/508)
and adds support for uploading files directly via an S3 client inside
Workhorse.

Full list of changes:
https://gitlab.com/gitlab-org/gitlab-workhorse/-/blob/master/CHANGELOG