[Fizz] Support useMemoCache in renderers with support for Client APIs

Mainly an oversight since we don't have types based off of feature flags.
Now that `enableUseMemoCache` is shipped, `useMemoCache` can be non-nullable.

Discovered during integration testing with Next.js where SSR threw with `TypeError: dispatcher.useMemoCache is not a function` but ultimately recovered due to client-side rendering.

Author: eps1lon

packages/react-reconciler/src/ReactInternalTypes.js

@@ -430,7 +430,7 @@ export type Dispatcher = {
   ): T,
   useId(): string,
   useCacheRefresh?: () => <T>(?() => T, ?T) => void,
-  useMemoCache?: (size: number) => Array<any>,
+  useMemoCache: (size: number) => Array<any>,
   useHostTransitionStatus: () => TransitionStatus,
   useOptimistic: <S, A>(
     passthrough: S,

packages/react-server/src/ReactFizzHooks.js

@@ -834,6 +834,7 @@ export const HooksDispatcher: Dispatcher = supportsClientAPIs
       useActionState,
       useFormState: useActionState,
       useHostTransitionStatus,
+      useMemoCache,
     }
   : {
       readContext,