[dynamicIO] Update prerender to use Fizz prerender (#71580)
Previously the `prerender` function for Fizz was gated to experimental
but in our latest React sync we now have access to it in the canary
channel. This updates the prerender pathway for non-experimental react
to use `prerender` rather than `renderToReadableStream`.
`prerender` has a few benefits in that it does breadth first rendering
at Suspense boundaries so you can ensure fallback UIs are fully rendered
wherever possible if you end up abortint the render.
currently stacked on #71579
