[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: 3454cfdb5a targetRevisionAtLastExport: 1804b1343

implementation-contributed/curation_logs/javascriptcore.json

 {
-  "sourceRevisionAtLastExport": "3454cfdb5a",
-  "targetRevisionAtLastExport": "1804b1343",
+  "sourceRevisionAtLastExport": "ffc7368147",
+  "targetRevisionAtLastExport": "ac84caea5",
   "curatedFiles": {
     "/stress/Number-isNaN-basics.js": "DELETED_IN_TARGET",
     "/stress/Object_static_methods_Object.getOwnPropertyDescriptors-proxy.js": "DELETED_IN_TARGET",