chore: Update with-ultracite example (#14335)
## Summary
- update Next.js, React, React DOM, Biome, Ultracite, Turbo, and related
type packages to their latest stable releases
- pin pnpm 12.6.0 with the current `devEngines.packageManager`
declaration and refresh the pnpm lockfile
- align the Biome schema reference with the installed CLI
- update README commands to consistently use the declared package
manager
Co-authored-by: vercel-gh-bot-5[bot] <312521305+vercel-gh-bot-5[bot]@users.noreply.github.com>
Co-authored-by: Anthony Shew <anthony.shew@vercel.com>