r-v8: new package at 3.4.0 (#20056)
r-v8: new package at 3.4.0 (#20056)

* r-v8: new package at 3.4.0

* r-v8: remove duplicate line
iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack,LLNL/spack,iulian787/spack,iulian787/spack,LLNL/spack,LLNL/spack,iulian787/spack