MR preview environments do not contain any content

Context

After MR preview environments (#1 - closed) we now have preview environments for merge requests, but they do not yet know how to display their contents.

Expected behaviour

The MR preview environment looks like the live environment.

• https://lab.allmende.io/libernetes/libernet.es/-/environments/82?tab=deployment-history
• https://libernet.es/

Observed behaviour

The last MR preview environment of Feat: MR preview environments (!6 - merged) loads the page and its background, but is otherwise empty.

• https://lab.allmende.io/libernetes/libernet.es/-/environments/83?tab=deployment-history
• https://libernetes.pages.allmende.io/-/libernet.es/-/jobs/2252/artifacts/public/index.html