Added v3 of Laghos (#15806)
Added v3 of Laghos (#15806)

* Added v3 of Laghos

Added v3 of Laghos as per
https://github.com/CEED/Laghos/blob/v3.0/README.md

* Update var/spack/repos/builtin/packages/laghos/package.py

Changed develop->master as per PR

Co-Authored-By: Adam J. Stewart <023e75a89b1f5ca1e59909f8756c185885836ad9@gmail.com>

* Made Metis Dependency Explicit

Added explicit metis dependency

* Folded @develop Laghos Deps in to @3.0:

Theoretically there will be a difference between develop and 3.0: in the
future but currently there is not

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