Merge pull request #7602 from kpayson64/downgrade_setuptools.py

Downgrade docker setuptools

tools/run_tests/build_python.sh

@@ -155,7 +155,9 @@ pip_install_dir() {
   cd $PWD
 }
 
-$VENV_PYTHON -m pip install --upgrade pip setuptools
+$VENV_PYTHON -m pip install --upgrade pip
+# TODO(https://github.com/pypa/setuptools/issues/709) get the latest setuptools
+$VENV_PYTHON -m pip install setuptools==25.1.1
 $VENV_PYTHON -m pip install cython
 pip_install_dir $ROOT
 $VENV_PYTHON $ROOT/tools/distrib/python/make_grpcio_tools.py