paperless wasn't building because django-cors-headers didn't build anymore with the pinned django version. I tested the paperless service (editd a few documents) and it works fine, even with django unpinned.
Every major version will have only a single LTS release, which is the one we typically keep in Nixpkgs. https://www.djangoproject.com/download/ This reverts commit af8a48c3c1.
af8a48c3c1
Paperless was dependent on older older versions of recently updated Python packages.