requirements-dev: Add types-setuptools for mypy runs

This will be added to the dockerfile so it will no longer need to be
downloaded

Change-Id: I1fd37564954f30eaae99c070ebfb1b5343f5d298

requirements-dev.txt

@@ -9,4 +9,5 @@ flake8==3.8.4
 grpcio-tools>=1.53.2
 twine==4.0.1
 types-attrs>=19.1.0
+types-setuptools>=69.0.0.0
 wheel==0.38.4