ModeSpec accepts bend_radius = np.nan, but error in runtime

[FilipeFcp]

I noticed that it is possible to pass the bend_radius argument of the ModeSpec object as np.nan. However, this will cause an error in runtime.

I believe it is worth to add a validator for that.

[momchil-flex]

This is unlikely to be limited to bend_radius, but rather to anything that's e.g. a float. There may be some native pydantic way to validate nans.

[caseyflex]

Yeah something like

class Finite(BaseModel):
    value: confloat(allow_inf_nan=False)

https://stackoverflow.com/questions/72472526/how-to-filter-out-nan-by-pydantic

We would have to replace float -> Finite everywhere. There was some discussion about changing our use of pydantic so I think this should wait (and is anyway pretty low priority)