feat(ci): add GitHub Actions job to publish the package

[himkt]

Created the action job to automate the publish pipeline based on https://github.com/pypa/gh-action-pypi-publish.

[himkt]

We have published torch-dftd with sdist and wheel for the previous versions. Since a wheel distribution covers all the environment that we want to support (only requiring Python3), I think it's enough to publish with one of these formats.

[ShigeruIwase-PFN]

I have no strong opinion about this. (Either is fine for me)

[ShigeruIwase-PFN]

(MEMO) Workflow filename (.github/workflows/publish.yml) is consistent with the registered one.

[ShigeruIwase-PFN]

Don't we need to set the PyPI repository url as well?

   environment:
     name: pypi
     url: https://pypi.org/p/<your-pypi-project-name>

ref: https://github.com/pypa/gh-action-pypi-publish

[ShigeruIwase-PFN]

How about testing using TestPyPI, just in case?

[himkt]

• I created GitHub Environment release. Now the environment is referred from the workflow ffe1943.
• I don't think we need TestPyPI (I think it's acceptable to run only on PyPI. In addition, there is no project torch-dftd on TestPyPI now).

[ShigeruIwase-PFN]

LGTM for me