update license file

[bollwyvl]

Congratulations on 0.23.0! 🎉

While working this downstream on conda-forge, noted that the pyproject.toml references COPYING as the license-file, but the repo's file is LICENSE. This PR updates it to align with the file that exists.

A broader note, related to #88: has the abi3 route been considered for this package? While I'm not qualified to assess whether this would be a good thing from a performance perspective, much less propose the changes, as a repackager, this would slash the number of CPython builds by a large margin. PyPy and 3.13t would no doubt need special consideration.

[Julian]

Thanks, sloppy copy pasting clearly, will merge after CI and send out a new release

A broader note, related to #88: has the abi3 route been considered for this package? While I'm not qualified to assess whether this would be a good thing from a performance perspective, much less propose the changes, as a repackager, this would slash the number of CPython builds by a large margin. PyPy and 3.13t would no doubt need special consideration.

I'm not sure either honestly without research, I'm sure I've looked into it at some point but I'd have to do some work again to understand the implications...

[bollwyvl]

Shipped 0.23.1 on conda-forge, thanks!