Bump vite from 8.0.16 to 8.2.1 in /demo

Bumps [vite](https://github.com/vitejs/vite/tree/HEAD/packages/vite) from 8.0.16 to 8.2.1.
- [Release notes](https://github.com/vitejs/vite/releases)
- [Changelog](https://github.com/vitejs/vite/blob/main/packages/vite/CHANGELOG.md)
- [Commits](https://github.com/vitejs/vite/commits/v8.2.1/packages/vite)

---
updated-dependencies:
- dependency-name: vite
  dependency-version: 8.1.2
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]