Lassen: No MPI4 Support

`mpi4py>=4.0` were released and support MPI 4 features.
But Lassen does not support MPI 4 in the IBM Spectrum
rolling releases.

Thus, limit the upper versions of `mpi4py` for now.

Also making the compilers for `h5py` a bit more robust, using
the Lassen-specific wrapper name (hey, thanks for being special).
https://hpc.llnl.gov/documentation/tutorials/using-lc-s-sierra-systems#Compilers

Tools/machines/lassen-llnl/install_v100_dependencies_toss3.sh

@@ -119,13 +119,15 @@ python3 -m pip install --upgrade build
 python3 -m pip install --upgrade packaging
 python3 -m pip install --upgrade wheel
 python3 -m pip install --upgrade setuptools[core]
-python3 -m pip install --upgrade cython
+python3 -m pip install --upgrade scikit-build-core
+python3 -m pip install --upgrade "cython>=3"
 python3 -m pip install --upgrade numpy
 python3 -m pip install --upgrade pandas
 CMAKE_PREFIX_PATH=/usr/lib64:${CMAKE_PREFIX_PATH} python3 -m pip install --upgrade -Ccompile-args="-j10" -Csetup-args=-Dblas=BLAS -Csetup-args=-Dlapack=BLAS scipy
-python3 -m pip install --upgrade mpi4py --no-cache-dir --no-build-isolation --no-binary mpi4py
+# Lassen does not support MPI v4+ yet
+MPI4PY_BUILD_BACKEND="scikit-build-core" python3 -m pip install --upgrade "mpi4py<4" --no-cache-dir --no-build-isolation --no-binary mpi4py
 python3 -m pip install --upgrade openpmd-api
-CC=mpicc H5PY_SETUP_REQUIRES=0 HDF5_DIR=${SW_DIR}/hdf5-1.14.1.2 HDF5_MPI=ON python3 -m pip install --upgrade h5py --no-cache-dir --no-build-isolation --no-binary h5py
+CC=mpigcc H5PY_SETUP_REQUIRES=0 HDF5_DIR=${SW_DIR}/hdf5-1.14.1.2 HDF5_MPI=ON python3 -m pip install --upgrade h5py --no-cache-dir --no-build-isolation --no-binary h5py
 MPLLOCALFREETYPE=1 python3 -m pip install --upgrade matplotlib==3.2.2  # does not try to build freetype itself
 echo "matplotlib==3.2.2" > ${build_dir}/constraints.txt
 python3 -m pip install --upgrade -c ${build_dir}/constraints.txt yt