Nonrad

- implements the Sommerfeld parameter in 1 and 2 dimensions [see J. Phys.: Condens. Matter 36, 195902 (2024)]
- faster overlap evaluation through Hermite-Gauss quadrature
- some warnings when the number of initial/final states is not high enough to cover the crossing point between the potential energy surfaces
- switch to pdm for package management

- support python 3.9
- replace default interpolator with the PCHIP interpolator, which provides much better results when the overlaps are small (important for nonradiative rate evaluations)

- updated citation information
- set ndmin=1 to ensure iterable numpy arrays
- updated `get_Q_from_struct` to handle edge cases more gracefully

- Update to maintain compatibility with new versions of pymatgen
- fix some mypy issues introduced in a new version

Made get_Q_from_struct more robust to handle the case when an atom may move but one of it's coordinates doesn't change.

Minor bug fix in get_Wif_from_WSWQ