closes #15372

This PR extends the SvelteKit peerDep range to include TS 6.0. It also
upgrades our apps/packages using TS purely as a devDependency to use 6.0
(this excludes `kit` because we use TS to generate public types and that
can be a breaking change. `package` is also excluded because it can't
support TS6 until svelte2tsx does).

### TODOs

- [x] update `svelte-check`
sveltejs/language-tools#2988

Required for `@sveltejs/package` if we want to support TS6 in the
future:
- [ ] update `svelte2tsx`
sveltejs/language-tools#2985
- [ ] update `svelte-preprocess`
sveltejs/svelte-preprocess#675

Required for SvelteKit 3 when we switch over to TS6 completely
- [x] update `@sveltejs/eslint-config`
sveltejs/eslint-config#67
- [ ] update `dts-buddy` sveltejs/dts-buddy#123

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