Spack py-gmxapi

The spack develop branch now includes a py-gmxapi package that should be compatible with MPI and non-MPI gromacs packages, versions 2022.1 and later.

I hope this will help HPC staff to provide optimal GROMACS+MPI+Python+gmxapi environments for their users. It could also just be handy for people who prefer Spack environments to other environment isolation/management schemes.

If you find any problems, you can tag my GitHub ID @eirrgang when opening issues on the Spack Issue tracker, but this forum thread (or the GROMACS Slack workspace) could be a good place for initial discussion.

Also, if you would be willing to help keep the recipe up-to-date, you can add your GitHub ID to the maintainers line to be notified of changes in need of review.