Fling: Configure `virtualViewPrerenderRatio as Operational

Summary:
Reclassifies the `virtualViewPrerenderRatio` feature flag as operational.

Changelog:
[Internal]

Differential Revision: D90336116

Author: yungsters

packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js

@@ -923,10 +923,9 @@ const definitions: FeatureFlagDefinitions = {
     virtualViewPrerenderRatio: {
       defaultValue: 5,
       metadata: {
-        dateAdded: '2025-05-30',
         description: 'Initial prerender ratio for VirtualView.',
         expectedReleaseValue: 5,
-        purpose: 'experimentation',
+        purpose: 'operational',
       },
       ossReleaseStage: 'none',
     },