Bump @vitejs/plugin-react from 4.2.1 to 4.3.1 in /modules/demo

Bumps [@vitejs/plugin-react](https://github.com/vitejs/vite-plugin-react/tree/HEAD/packages/plugin-react) from 4.2.1 to 4.3.1.
- [Release notes](https://github.com/vitejs/vite-plugin-react/releases)
- [Changelog](https://github.com/vitejs/vite-plugin-react/blob/main/packages/plugin-react/CHANGELOG.md)
- [Commits](https://github.com/vitejs/vite-plugin-react/commits/v4.3.1/packages/plugin-react)

---
updated-dependencies:
- dependency-name: "@vitejs/plugin-react"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>