• Raise DNSError(ARES_ENODATA) from query() when the answer section has no records of the requested qtype, restoring the pycares 4.x NODATA contract and avoiding AttributeError for CNAME/SOA/PTR callers (#254).
• Add the missing build-backend entry to pyproject.toml so PEP 517 builds from the sdist work without falling back to the deprecated legacy setuptools backend (#252).