Add publish-pypi workflow

[dwhswenson]

Getting ready to do the release! We'll need this workflow in place first

[Copilot]

Pull Request Overview

Adds a GitHub Actions workflow to automatically publish the package to PyPI when a new release is published. This prepares the repository for automated package distribution.

• Configures workflow to trigger on GitHub release publication
• Sets up Python environment and builds the package using standard tools
• Uses PyPA's official action for secure PyPI publishing with OIDC

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[Copilot]

Pin the action to a specific commit hash instead of using the mutable 'release/v1' tag to prevent supply chain attacks. For example, use a format like 'pypa/gh-action-pypi-publish@81e9d935c883d0b210363ab89cf05f3894778450'.

Suggested change

	uses: pypa/gh-action-pypi-publish@release/v1
	uses: pypa/gh-action-pypi-publish@81e9d935c883d0b210363ab89cf05f3894778450

[dwhswenson]

I understand the recommendation, but since I'm going to do a video on this, I'm going to keep it clear (and recommend that viewers check whatever the most recent hash is).