dillon1000/react

Add test for throttling suspended siblings (#28361)

# Overview

Adds a test to show the combination of the new throttling behavior and
not pre-rendering siblings results in pushing out content that could
have rendered much faster.

- Without the new throttling, the sibling content would render in 30ms.
- Without removing pre-rendering, the sibling content would render in
0ms.
- With both, the sibling content takes 600ms.

## Example


https://github.com/facebook/react/assets/2440089/abd62dc4-93f9-4b7b-a5aa-b795827c1a3a