Drop vigranumpy from CMake
Drop vigranumpy from CMake

This was only really needed when the VIGRA build was supported. Given
that is no longer the case, a bunch of related code can be dropped.

DudLab/rank_filter,jakirkham/rank_filter,jakirkham/rank_filter,DudLab/rank_filter,nanshe-org/rank_filter,nanshe-org/rank_filter,jakirkham/rank_filter,nanshe-org/rank_filter,DudLab/rank_filter