audioop removed in python 3.13

[kcsapp]

This requirement of sf2utils was removed in python 3.13; see docs.python.org, and PEP 594 for details.
The fix for me was to simply manually install audioop-lts: https://pypi.org/project/audioop-lts/
PEP 594 also mentions that there is an equivalent function in the wave module; it's a private function (wave._byteswap) with a pure python implementation, whereas the audioop implementation is written in C. The implementation in audioop-lts appears to be a copy of the original C implementation.