Update "Nested BBG" test to work locally

tests/validation/config.json

@@ -3,7 +3,7 @@
   "tests": [
     {
       "title": "Nested BBG",
-      "playgroundId": "#ZG0C8B#0",
+      "playgroundId": "#ZG0C8B#1",
       "referenceImage": "nested_BBG.png"
     },
     {