Add Python 3.14 support

[d33bs]

Python 3.14 is now available and we can add compatibility with this.

[d33bs]

Attempted this today and found we're constrained by Python 3.14 and NumPy dependencies. Used this pyproject.toml configuration: https://gist.github.com/d33bs/6510a71d42360a43f8a55f923d4fdd5a