Upgrade to GitLab Workhorse v8.23.0

This is needed as the final step to rolling out serving static objects
via a CDN:
https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/6829.

This version disables the setting of the `Cache-Control`
header within Workhorse:
https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/462.

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

GITLAB_WORKHORSE_VERSION

-8.22.0
+8.23.0