fix: include universal load assets as server assets

[teemingc]

fixes #13503

This PR includes the assets imported through Vite in universal load function files as server assets so that when the universal load function tries to fetch the URL of the imported asset, the file can be read on the server instead of returning a 404 not found text response.

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🦋 Changeset detected

Latest commit: 3233cf2

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

This PR includes changesets to release 1 package

Name	Type
@sveltejs/kit	Patch

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-13531-svelte.vercel.app/

[elliott-with-the-longest-name-on-github]

I approved it but haven't merged it just so you can add those periods before merging 😆 Feel free to merge when you're ready

[teemingc]

Thanks! 😆