Add info on yarn 4 to the docs.

[Lenostatos]

Describe the problem

At and around https://svelte.dev/docs/kit/faq#How-do-I-use-X-with-SvelteKit-How-do-I-use-with-Yarn-3 I can't find any mention of yarn 4. Would it be possible to add a short section on that in the docs?

Describe the proposed solution

Unfortunately I have no idea which issues there are between SvelteKit and yarn 4, but I did find out, that yarn's E2E testing has been reporting errors with SvelteKit since Feb 27, 2024:

https://github.com/yarnpkg/berry/actions/workflows/e2e-svelte-kit-workflow.yml

Maybe you could put your knowledge about the current status into the docs? And if it's just a "Yarn 4 currently has issues with SvelteKit so we recommend not using it for the time being."

Alternatives considered

No response

Importance

nice to have

Additional Information

No response