Add pdf preview and improved memoizing
Adds viewer for pdf files.
We’ve updated our runner tagging system. If you’re using our shared runners for your CI pipelines, please review the new tags here: https://docs.mpcdf.mpg.de/bnb/220.html#new-tags-for-mpcdf-gitlab-runners
The old tags will remain valid until the end of February 2026.
Adds viewer for pdf files.