[Suggestion]: Update the react-test-renderer page to React 19

[BartoszKlonowski]

Summary

This is to make sure that the react-test-renderer Deprecation Warnings page is up to date with the React 19.

Page

No response

Details

It's good to keep pages up to speed with the latest and greatest!

[vkhoang]

Hi there! I took a look at the react-test-renderer portion and noticed that it already has a deprecation warning for React 19, along with a recommendation to use an alternative testing library. If there's any additional changes that need to be done I would be happy to work on it!

[rickhanlonii]

Thanks @vkhoang!

@BartoszKlonowski where is the page you're saying we should add a note? Is that the legacy page? We don't update that site any more...