Fix (partially) Svelte E2E test

[clemyan]

What's the problem this PR addresses?

The SvelteKit E2E test has been failing

How did you fix it?

• create-svelte discontinued the next dist-tag, use latest instead
• I don't know how it was but yes cannot defeat create-svelte interactivity now, so I just use its node API instead
• Also added a TypeScript test

The test should still be failing due to sveltejs/kit#11433 (comment), but at least it is an actual failure of the E2E test, not of our setup. 🤷

Closes #6345

Checklist

• I have read the Contributing Guide.

• I have set the packages that need to be released for my changes to be effective.

• I will check that all automated PR checks pass before the PR gets reviewed.