Upgrade docs/preview to Vite and TW4

[frandiox]

Start using Vite in our docs/preview utility and upgrade to Tailwind v4 alpha which uses a Vite plugin. Otherwise we'll have deps incompatibilities with the incoming --styling tailwind feature.

Edit: we might need #2190 merged to be sure test/typecheck passes in this PR.

[github-actions]

We detected some changes in packages/*/package.json or packages/*/src, and there are no updates in the .changeset.
If the changes are user-facing and should cause a version bump, run npm run changeset add to track your changes and include them in the next release CHANGELOG.
If you are making simple updates to examples or documentation, you do not need to add a changeset.

[shopify]

Oxygen deployed a preview of your fd-docs-preview-vite-tw4 branch. Details:

Storefront	Status	Preview link	Deployment details	Last update (UTC)
metaobjects	✅ Successful (Logs)	Preview deployment	Inspect deployment	July 4, 2024 3:17 AM
third-party-queries-caching	✅ Successful (Logs)	Preview deployment	Inspect deployment	July 4, 2024 3:18 AM
Skeleton (skeleton.hydrogen.shop)	✅ Successful (Logs)	Preview deployment	Inspect deployment	July 4, 2024 3:17 AM
classic-remix	✅ Successful (Logs)	Preview deployment	Inspect deployment	July 4, 2024 3:17 AM
custom-cart-method	✅ Successful (Logs)	Preview deployment	Inspect deployment	July 4, 2024 3:17 AM
optimistic-cart-ui	✅ Successful (Logs)	Preview deployment	Inspect deployment	July 4, 2024 3:17 AM

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[blittle]

Tested, looks good. Thx for doing this.