devel/py-pyyaml: Update 6.0.1 => 6.0.2, switch to lang/cython3 to avoid other conflicts
Changelog:
- Support for Cython 3.x and Python 3.13.
https://github.com/yaml/pyyaml/releases/tag/6.0.2
PR: 289718
Approved by: python (maintainer, timeout 2 weeks)