workaround bug generating invalid metadata (#347)

Author: jakkdl

setup.py

@@ -31,6 +31,7 @@ def local_file(name: str) -> Path:
         "Changelog": "https://flake8-async.readthedocs.io/en/latest/changelog.html",
     },
     license="MIT",
+    license_files=[],  # https://github.com/pypa/twine/issues/1216
     description="A highly opinionated flake8 plugin for Trio-related problems.",
     zip_safe=False,
     install_requires=["flake8>=6", "libcst>=1.0.1"],