v3 onboading pinned versions

[endigo9740]

Linked Issue

Closes #3179

Description

Updates SvelteKit and Next.js onboarding to use pinned version that will avoid Tailwind v4 for now.

Checklist

Please read and apply all contribution requirements.

• Your branch should be prefixed with: docs/, feature/, chore/, bugfix/
• Skeleton v3 contributions must target the next branch (NEVER dev or master)
• Documentation should be updated to describe all relevant changes
• Run pnpm check in the root of the monorepo
• Run pnpm format in the root of the monorepo
• Run pnpm lint in the root of the monorepo
• Run pnpm test in the root of the monorepo
• If you modify /package projects, please supply a Changeset

Changsets

View our documentation to learn more about Changesets. To create a Changeset:

1. Navigate to the root of the monorepo in your terminal
2. Run pnpm changeset and follow the prompts
3. Commit and push the changeset before flagging your PR review for review.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 028f8e8

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

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