Remove holdouts field from test_config expected response

go-sdk v2.3.0 does not include holdouts field in OptimizelyConfig.
The holdouts field was added in a later commit (e70a8f3) after v2.3.0 was tagged.

Author: Mat001

tests/acceptance/test_acceptance/test_config.py

@@ -470,8 +470,7 @@
                 "16910084756"
             ]
         }
-    ],
-    "holdouts": []
+    ]
 }"""