fix: remove experimental from new arch (#705)

### Summary

New Arch is not experimental anymore! 🎉

### Test plan

N/A

Author: okwasniewski

packages/create-react-native-library/src/input.ts

@@ -88,8 +88,8 @@ const EXAMPLE_CHOICES = (
   ] as const
 ).filter((choice) => !choice.disabled);
 
-const NEWARCH_DESCRIPTION = 'requires new arch (experimental)';
-const BACKCOMPAT_DESCRIPTION = 'supports new arch (experimental)';
+const NEWARCH_DESCRIPTION = 'requires new arch';
+const BACKCOMPAT_DESCRIPTION = 'supports new arch';
 
 const TYPE_CHOICES: {
   title: string;