gitlab: Remove unused Kokkuri environment variables
S3 cache export was a brief experiment and is no longer supported by Kokkuri.
How to register an account on GitLab. To prevent spam, new accounts are locked until approved by an admin or the approver bot. You can also file an unlock request to expedite access.
Support: mw:GitLab, how to host a project on GitLab, #wikimedia-gitlab on libera.chat, #GitLab on Phabricator.
S3 cache export was a brief experiment and is no longer supported by Kokkuri.