pexsi: add openmp flags to fortran flags if dependencies use OpenMP (#19274)
pexsi: add openmp flags to fortran flags if dependencies use OpenMP (#19274)

Co-authored-by: Adam J. Stewart <023e75a89b1f5ca1e59909f8756c185885836ad9@gmail.com>
iulian787/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack,LLNL/spack,LLNL/spack,iulian787/spack