Sphericart

Simply adds builds for torch 2.6, and fixed some quirks of clang-format that triggered CI errors

- Minor bug fixes
- Runtime CUDA compilation via NVRTC
- CUDA wheels for `sphericart-torch` and `sphericart-jax`
- `metatensor` and `metatensor-torch` interfaces

- All APIs now offer spherical harmonics and solid harmonics (previously `normalized=True/False` respectively)
- New CUDA C++ and JAX APIs
- The Pytorch API now provides `SphericalHarmonics` and `SolidHarmonics` as subclasses of `torch.nn.Module`
- The Pytorch API warns (once) about second derivatives
- Solved bug when the spherical harmonics are called with zero points to calculate (all APIs)
- Various documentation improvements

/

julia-v0.0.3
This is the first public release of SpheriCart.jl, the Julia version of sphericart