Compile as c11 instead of c99 for cpython3.13 header compatibility

setup.py

@@ -33,7 +33,7 @@
         source_files,
         include_dirs=include_dirs,
         depends=depends_files,
-        extra_compile_args=["-std=c99"],
+        extra_compile_args=["-std=c11"],
     )
 ]