numpy_interface: handle mpi4py not being available
Just because MPI and Python is enabled does not imply that mpi4py is available.
See paraview/paraview#18492 (closed).
Cc: @utkarsh.ayachit
Backport: paraview/release
Just because MPI and Python is enabled does not imply that mpi4py is available.
See paraview/paraview#18492 (closed).
Cc: @utkarsh.ayachit
Backport: paraview/release