devel/py-maturin: Update to 1.7.8

• Remove no longer required patch for the "xwin" crate.

Changelogs since 1.7.4:

https://github.com/PyO3/maturin/releases/tag/v1.7.8
https://github.com/PyO3/maturin/releases/tag/v1.7.7
https://github.com/PyO3/maturin/releases/tag/v1.7.6
https://github.com/PyO3/maturin/releases/tag/v1.7.5