Remove enableCache override that's no longer correct

Author: sebmarkbage

scripts/jest/TestFlags.js

@@ -81,11 +81,6 @@ function getTestFlags() {
 
       ...featureFlags,
       ...environmentFlags,
-
-      // FIXME: www-classic has enableCache on, but when running the source
-      // tests, Jest doesn't expose the API correctly. Fix then remove
-      // this override.
-      enableCache: __EXPERIMENTAL__,
     },
     {
       get(flags, flagName) {