Declare the function as noexcept when it is not raising exception.

[matusvalo]

Cython 3 will require noexcept keyword in the declaraction of the function not raising an exceptions. See https://cython.readthedocs.io/en/latest/src/userguide/migrating_to_cy30.html#exception-values-and-noexcept

Fixes #26

[jborean93]

Thanks for the fix here!