fix: Avoid 'key prop spread into JSX' warning.

React 18.3 detects `key` being spread and doesn't like it.

src/inputs/internal/VirtualizedOptions.tsx

@@ -64,7 +64,7 @@ export function VirtualizedOptions<O>(props: VirtualizedOptionsProps<O>) {
             // otherwise render just 1 row. A better way to do this would be to jest.mock
             // out Virtuoso with an impl that just rendered everything, but doing this for now.
             initialItemCount: items.length,
-            key: items.length,
+            itemsCount: items.length,
           }
         : {
             // Ensure the selected item is visible when the list renders