argobots: mark 1.0 as preferred (#16458)
argobots: mark 1.0 as preferred (#16458)

By default, Spack chooses 1.0rc2 instead of 1.0 though 1.0 is the stable and
newer release.  We manually mark the version 1.0 as preferred.
iulian787/spack,LLNL/spack,iulian787/spack,iulian787/spack,LLNL/spack,LLNL/spack,iulian787/spack,iulian787/spack,LLNL/spack,LLNL/spack