hwloc: Add netloc variant (#16001)
hwloc: Add netloc variant (#16001)

hwloc depends on MPI when netloc is enabled. Note that OpenMPI depends on
netloc, so hwloc cannot use OpenMPI as the MPI provider when netloc is
enabled (this would result in a cyclic dependency).
iulian787/spack,iulian787/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack,LLNL/spack,LLNL/spack,iulian787/spack,LLNL/spack