Allow MPI4PY to be part of a static mpi+python build

While it can't be built statically, it should allow static VTK
builds to use it.

ThirdParty/mpi4py/vtk.module

@@ -3,7 +3,7 @@ NAME
 LIBRARY_NAME
   vtkmpi4py
 CONDITION
-  VTK_USE_MPI AND BUILD_SHARED_LIBS
+  VTK_USE_MPI
 PRIVATE_DEPENDS
   VTK::mpi
   VTK::Python