Enable cache in test renderer (#22580)

Author: josephsavona

packages/shared/forks/ReactFeatureFlags.test-renderer.www.js

@@ -23,7 +23,7 @@ export const enableUpdaterTracking = false;
 export const enableSuspenseServerRenderer = false;
 export const enableSelectiveHydration = false;
 export const enableLazyElements = false;
-export const enableCache = false;
+export const enableCache = true;
 export const enableSchedulerDebugging = false;
 export const disableJavaScriptURLs = false;
 export const disableInputAttributeSyncing = false;