fix: use correct python path for venv creation in windows

[tisoft]

Python installations on windows do not have a bin directory. This is already taken into account in different places, but when automatically creating venvs bin is always used.

This change was my attempt to fix this as a non-rust developer with minimal code changes and reusing the existing python_path function. I had to make the python plugin public, which is probably not the way to do it. 😄

So I am open to suggestions on how to properly fix this.

#4152

[autofix-ci]

Hi! I'm autofix.ci, a bot that automatically fixes trivial issues such as code formatting in pull requests.

I would like to apply some automated changes to this pull request, but it looks like I don't have the necessary permissions to do so. To get this pull request into a mergeable state, please do one of the following two things:

1. Allow edits by maintainers for your pull request, and then re-trigger CI (for example by pushing a new commit).
2. Manually fix the issues identified for your pull request (see the GitHub Actions output for details on what I would like to change).