Fix bug in py-dgl installation, add unit tests (#15617)
Fix bug in py-dgl installation, add unit tests (#15617)


LLNL/spack,LLNL/spack,LLNL/spack,iulian787/spack,iulian787/spack,iulian787/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack