Bump vite from 2.9.16 to 2.9.18 in /demos

Bumps [vite](https://github.com/vitejs/vite/tree/HEAD/packages/vite) from 2.9.16 to 2.9.18.
- [Release notes](https://github.com/vitejs/vite/releases)
- [Changelog](https://github.com/vitejs/vite/blob/v2.9.18/packages/vite/CHANGELOG.md)
- [Commits](https://github.com/vitejs/vite/commits/v2.9.18/packages/vite)

---
updated-dependencies:
- dependency-name: vite
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>