chore: upgrade vitest

[gtm-nayan]

renovate won't do it because semver

Before submitting the PR, please make sure you do the following

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• Prefix your PR title with feat:, fix:, chore:, or docs:.
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests and linting

• Run the tests with pnpm test and lint the project with pnpm lint

[Conduitry]

Is there any way to avoid the two simultaneous versions of esbuild this gives us?

[dominikg]

vite 4.4 uses 0.18 , latest vitest should too. pnpm dedupe could do, otherwise adding an override to package.json, but overriding it risks breaking something.

[benmccann]

We just need to merge sveltejs/kit#10330 and then update to the latest adapter-vercel in the sites directory here. Anyone want to give sveltejs/kit#10330 an approval? 😉

[benmccann]

It looks like happy-dom 9.20.3 is being used by vitest even before this PR, which means you should be able to address this TODO now:

svelte/packages/svelte/test/hydration/hydration.test.js

Line 2 in 02099d9

// TODO: https://github.com/capricorn86/happy-dom/issues/916

Mind sneaking a fix for that into this PR?

[gtm-nayan]

Looks like happy-dom has a few more bugs, just removed the todo for now. It's a small suite so we won't get much difference in speed either.