chore: get Vercel split platform tests running

[teemingc]

Don't think these will run for us on the version-3 branch unless they're also on the main branch

[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from 48c5afc:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/48c5afcdd18d4c14a9c5bb6ecf4d58feba0ad804

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16666

[changeset-bot]

⚠️ No Changeset found

Latest commit: 48c5afc

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-16666-svelte.vercel.app/

[teemingc]

/autofix

[Rich-Harris]

All the stuff about which things need to be on which branch for various workflows to succeed is truly breaking my brain