Provides a unique (but stable per useAction hook call) key to pass into the underlying useFetcher, which fixes a bug where multiple useAction hooks mounted simultaneously could be unintentionally linked.
The key is required because post Remix v2.2.0, the fetchers used internally by useAction do not behave the same as they did in Remix <=2.1.0 without passing in the key. If there is a more canonical way to achieve this, let me know, but I believe this now fully restores the prior remix-easy-mode behavior on all Remix versions.
If anyone runs into issues, please let me know by filing an issue. Just this once, feel free to at-tag me to make sure I see it quickly.