python3-txaio: Migrate setup.py to pyproject.toml
Fixes
WARNING: python3-txaio-25.9.2-r0 do_check_backend: QA Issue: inherits setuptools3 but has pyproject.toml with setuptools.build_meta, use the correct class [pep517-backend]
Signed-off-by: Khem Raj <raj.khem@gmail.com>