Eliminate 2 more remaining `React.AbstractComponent<...>` in react native

Summary:
In order to adopt react 19's ref-as-prop model, we need to eliminate all the places where they are treated differently. `React.AbstractComponent` is the worst example of this, and we need to eliminate it.

This diff replaces 2 more remaining ones in react-native. Now the only remaining one is the one synced from react repo.

Changelog: [Internal]

Reviewed By: alexmckenley

Differential Revision: D64722899

fbshipit-source-id: 2b2484c385fc5d6c173253f9bee66dfc736368a5