Draft: add python_version to version_option available message formats

[snosratiershad]

• fixes path and python version values for version message formatting #1756

Checklist:

• Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.
• Add or update relevant docs, in the docs folder and in code.
• Add an entry in CHANGES.rst summarizing the change and linking to the issue.
• Add .. versionchanged:: entries in any relevant code docs.
• Run pre-commit hooks and fix any issues.
• Run pytest and tox, no tests failed.

[AndreasBackx]

I've converted this to a draft to show that there's still outstanding work (see checklist).