vasp: libbeef, libxc, wannier90, v6.4.2, v6.3.1

[nolta]

This series of commits for vasp:

• adds versions 6.3.1 & 6.4.2;
• adds variants for libbeef, libxc, & wannier90 support;
• adds a new libbeef package.

[nolta]

@spackbot fix style

[spackbot-app]

Let me see if I can fix that for you!

[spackbot-app]

I was able to run spack style --fix for you!

spack style --fix

repos/spack_repo/builtin/packages/libbeef/package.py
repos/spack_repo/builtin/packages/vasp/package.py
�[1;34m==> �[0mrunning flake8
repos/spack_repo/builtin/packages/libbeef/package.py:30: [W391] blank line at end of file
�[1;34m==> �[0mrunning isort
�[1;34m==> �[0mrunning black

Keep in mind that I cannot fix your flake8 or mypy errors, so if you have any you'll need to fix them and update the pull request. If I was able to push to your branch, if you make further changes you will need to pull from your updated branch before pushing again.

I've updated the branch with style fixes.

But it looks like I'm not able to push to your branch. 😭️ Did you check Allow edits from maintainers when you opened the PR?

[nolta]

@snehring

[snehring]

The changes look fine to me. I don't have the vasp versions that are added on hand so I can't validate the checksums directly. 6.5.1 compiles with the added changes.

[tldahlgren]

Confirmed the homepage and version commit (libbeef); can't verify vasp since manual download.