chore: add python 3.14 to CI matrix (#917)

Added:
- Python 3.13 and 3.14 to CI testing matrix in community workflow
- Python 3.14 to CI testing matrix in core workflow
- Python 3.13 and 3.14 classifiers to pyproject.toml

Changed:
- Default Python version in setup-env action from 3.12 to 3.14

Removed:
- None

Closed #916

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Co-authored-by: David Ankin <daveankin@gmail.com>