Fix windows abi3 builds
It looks like setuptools-rust doesn't support abi3 builds targetting python 3.7 any more.
Since 3.7 is end of life anyway, I've bumped all the builds to target 3.8 instead.
Edited by Benjamin Winger
It looks like setuptools-rust doesn't support abi3 builds targetting python 3.7 any more.
Since 3.7 is end of life anyway, I've bumped all the builds to target 3.8 instead.