Support Python 3.14 and 3.15 in the Power Fx Python bridge #3094

Request

Please update the powerfx PyPI package to support Python 3.14 and 3.15.

Current behavior

powerfx 0.0.32–0.0.34 pins pythonnet==3.0.5. That pythonnet release has no matching distribution for Python 3.15, so resolution fails:

$ python3.15 -m pip install --dry-run 'powerfx>=0.0.32,<0.0.35'
ERROR: Cannot install powerfx==0.0.32, powerfx==0.0.33 and powerfx==0.0.34 because these package versions have conflicting dependencies.
...
Additionally, some packages in these conflicts have no matching distributions available for your environment:
    pythonnet

Pythonnet 3.2.1 now advertises Python 3.14 and 3.15 support (Requires-Python >=3.11,<3.16), so the bridge may be able to move to a compatible newer pythonnet range after API validation.

This currently causes Microsoft Agent Framework's declarative Power Fx functionality and tests to remain disabled on Python 3.14+.

Please evaluate compatibility with pythonnet 3.2.x, add Python 3.14/3.15 CI coverage, and publish an updated powerfx release.