Raise an exception if no versions remained after filtering

This can happen if the source package has been renamed while still generating a binary package with the same name. For example, Ruby bundler is no longer a separate source package, but is shipped in the rubygems package. Madison returns this for bundler:

---
bundler:
  2.2.5-2:
    bullseye:
      - all

The source pseudoarchitecture is missing from the list since it’s not a source package in bullseye anymore.

Apertis: T7811