Add built Python smoke test to macOS setup script

Prior to this smoke test, the macOS setup step wouldn't fail if the
Python that it built wasn't functional. This will make debugging Python
build issues easier in the future.

Signed-off-by: Christopher Crone <christopher.crone@docker.com>

script/setup/osx

@@ -98,6 +98,11 @@ if ! [[ $(${TOOLCHAIN_PATH}/bin/python3 --version) == *"${PYTHON_VERSION}"* ]];
   )
 fi
 
+#
+# Smoke test built Python.
+#
+openssl_version ${TOOLCHAIN_PATH}
+
 echo ""
 echo "*** Targeting macOS: ${DEPLOYMENT_TARGET}"
 echo "*** Using SDK ${SDK_PATH}"