Fix tsconfig used in create-svelte

[oekazuma]

The new SvelteKit project created by npm init svelte will by default overwrite the libs, modules, and targets added in #4791, so fix this.

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🦋 Changeset detected

Latest commit: 783a4b2

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

This PR includes changesets to release 1 package

Name	Type
create-svelte	Patch

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[Rich-Harris]

good catch, thank you!