update test to use revised playground, regenerated reference images

tests/validation/config.json

@@ -491,15 +491,15 @@
     },
     {
       "title": "GLTF Serializer with Negative World Matrix",
-      "playgroundId": "#KX53VK#24",
+      "playgroundId": "#KX53VK#27",
       "referenceImage": "glTFSerializerNegativeWorldMatrix.png"
     },
     {
       "title": "GLTF Serializer with Negative World Matrix (Right Handed)",
-      "playgroundId": "#KX53VK#24",
+      "playgroundId": "#KX53VK#27",
       "replace": "useRightHandedSystem = false, useRightHandedSystem = true",
       "referenceImage": "glTFSerializerNegativeWorldMatrix_Right.png"
-    },,
+    },
     {
       "title": "GLTF Buggy with Draco Mesh Compression",
       "playgroundId": "#JNW207#1",