blubber.yaml: Use blubber/buildkit v0.16.0
And remove whitespace surrounding the "=" in the syntax line.
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.
And remove whitespace surrounding the "=" in the syntax line.