Use pyo3 abi3 feature

[mrexodia]

Documentation: https://pyo3.rs/main/building-and-distribution#py_limited_apiabi3

Reference project: https://github.com/icicle-emu/icicle-python/blob/main/Cargo.toml#L15

This allows the built wheels to be compatible with future python versions without requiring a rebuild and it greatly reduces the amount of wheels to produce.

[imfing]

thank you for the suggestion, will look into this