add mpi to providers to remove virtual package error (#4608)
add mpi to providers to remove virtual package error (#4608)


krafczyk/spack,krafczyk/spack,skosukhin/spack,tmerrick1/spack,LLNL/spack,iulian787/spack,lgarren/spack,lgarren/spack,mfherbst/spack,TheTimmy/spack,TheTimmy/spack,TheTimmy/spack,iulian787/spack,EmreAtes/spack,tmerrick1/spack,skosukhin/spack,matthiasdiener/spack,lgarren/spack,iulian787/spack,TheTimmy/spack,mfherbst/spack,skosukhin/spack,lgarren/spack,LLNL/spack,lgarren/spack,krafczyk/spack,iulian787/spack,skosukhin/spack,krafczyk/spack,krafczyk/spack,matthiasdiener/spack,EmreAtes/spack,LLNL/spack,mfherbst/spack,tmerrick1/spack,skosukhin/spack,tmerrick1/spack,LLNL/spack,TheTimmy/spack,LLNL/spack,mfherbst/spack,EmreAtes/spack,matthiasdiener/spack,matthiasdiener/spack,tmerrick1/spack,iulian787/spack,EmreAtes/spack,mfherbst/spack,matthiasdiener/spack,EmreAtes/spack