mpiCheckPhaseHook: use low-level env HWLOC_XMLFILE in all MPI implementations (#399205)

      # The solution is to use a preset cpu topology file and disable ucx model.

      # Disable sysfs cpu topology directory discovery.

      export PRTE_MCA_hwloc_use_topo_file="@topology@"

      export HWLOC_XMLFILE="@topology@"

      # Use the network model ob1 instead of ucx.

      export OMPI_MCA_pml=ob1

      ;;

    MVAPICH)

      # Disable CPU pinning

      export MV2_ENABLE_AFFINITY=0

      # Disable sysfs cpu topology directory discovery.

      export HWLOC_XMLFILE="@topology@"

      ;;

  esac