Do not install the *.c sources (MagicStack#73)

Co-authored-by: Fantix King <[email protected]>

Author: hroncok

setup.py

@@ -211,6 +211,7 @@ def build_extensions(self):
         ),
     ],
     include_package_data=True,
+    exclude_package_data={"": ["*.c", "*.h"]},
     test_suite='tests.suite',
     setup_requires=setup_requires,
     extras_require={