Respond with status code 413 if request body is too large

[repsac-by]

Fixes #6920

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🦋 Changeset detected

Latest commit: 400be4c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@sveltejs/adapter-node	Patch
@sveltejs/adapter-vercel	Patch
@sveltejs/kit	Patch
@sveltejs/adapter-auto	Patch

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[dummdidumm]

I'm not well-versed with the details of this code section - could you explain briefly why this change is necessary?

[repsac-by]

This returns an error in the RequestHandler and from there the status code gets into the Response, otherwise the connection is simply terminated without a response. cancelled = true is needed so that controller.close() does not occur in the req.on('end', () => ...) because calling close() on a closed controller causes an unhandled exception.