Bump vite and vuepress in /site

Bumps [vite](https://github.com/vitejs/vite/tree/HEAD/packages/vite) to 5.0.12 and updates ancestor dependency [vuepress](https://github.com/vuejs/vuepress/tree/HEAD/packages/vuepress). These dependencies need to be updated together.


Updates `vite` from 3.0.9 to 5.0.12
- [Release notes](https://github.com/vitejs/vite/releases)
- [Changelog](https://github.com/vitejs/vite/blob/v5.0.12/packages/vite/CHANGELOG.md)
- [Commits](https://github.com/vitejs/vite/commits/v5.0.12/packages/vite)

Updates `vuepress` from 2.0.0-beta.51 to 2.0.0-rc.0
- [Release notes](https://github.com/vuejs/vuepress/releases)
- [Changelog](https://github.com/vuejs/vuepress/blob/master/CHANGELOG.md)
- [Commits](https://github.com/vuejs/vuepress/commits/HEAD/packages/vuepress)

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

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