[javascriptcore-test262-automation] Updated curation log with latest revision...

[javascriptcore-test262-automation] Updated curation log with latest revision sha's from export and changed files.
    sourceRevisionAtLastExport: 54374edc2b targetRevisionAtLastExport: bbc9ae15

implementation-contributed/curation_logs/javascriptcore.json

 {
-  "sourceRevisionAtLastExport": "54374edc2b",
-  "targetRevisionAtLastExport": "bbc9ae15d9",
+  "sourceRevisionAtLastExport": "ac12ca41a6",
+  "targetRevisionAtLastExport": "b47fed1a36",
   "curatedFiles": {
     "/stress/Number-isNaN-basics.js": "DELETED_IN_TARGET",
     "/stress/Object_static_methods_Object.getOwnPropertyDescriptors-proxy.js": "DELETED_IN_TARGET",