Exclude stubgen from mypyc complication to avoid inheritance issues

Author: chadrik

setup.py

@@ -110,6 +110,7 @@ def run(self):
             "version.py",
             # Skip these to reduce the size of the build
             "stubtest.py",
+            "stubgen.py",
             "stubgenc.py",
             "stubdoc.py",
             "stubutil.py",