Spack/CI updates

[rbberger]

PR Summary

• Updates ports-of-call spackage
• Removes copy of py-sphinx-multiversion spackage, which is no longer needed since the testing upstream is now v0.18
• Removes Spack dependencies for ports-of-call that select a portability_strategy
• Adds missing +cuda_constexpr for +kokkos+cuda
• Closes #50
• Closes #52
• Updates Catch2 requirement to 2.13.7 to fix compilation issues on GCC 11

PR Checklist

• [ ] Code is formatted. (You can use the format_spiner make target.)
• [ ] Adds a test for any bugs fixed. Adds tests for new features.

[rbberger]

@Yurlungur Unlike ports-of-call, this repo has a GitLab pipeline that pulls in its doc dependencies via Spack. But I might still remove the +doc variant in the public facing Spack package in upstream.

[Yurlungur]

Assume this is for the header-only version of ports-of-call with portability strategy removed?

@Yurlungur Unlike ports-of-call, this repo has a GitLab pipeline that pulls in its doc dependencies via Spack. But I might still remove the +doc variant in the public facing Spack package in upstream.

I'm in favor of this. Let's just remove the doc build from the gitlab workflow, since github is building for us

[rbberger]

@Yurlungur Yes, please see my comment in the re-git instance. It does come with a cost, not sure how important that other pages instance is.

[rbberger]

@Yurlungur the GitHub action failure seems to be caused by a newer ubuntu image that now uses GCC 11.3 instead of 9.4.0

[rbberger]

@Yurlungur Updating the Catch2 dependency fixed the issue. Also cleaned up the broken submodule state (.gitmodules entry was ignored, since the folder wasn't commited anymore)