- requires-python >= 3.12; abi3 limited API tag cp310 -> cp312
- util.Buffer now imported directly from collections.abc (no fallback)
- release.py: ABI3 wheel covers 3.12-3.15; PyPy wheels dropped (PyPy
has no 3.12 support yet)
Matrix job builds and tests wheels on linux/macos/windows (no Gitea
release, unlike mediahive); publish job uploads the merged dist/ to PyPI
only after all platforms succeed. release.py gains --no-upload for the
matrix jobs.