build: bump rollup and vitepress in /docs

Bumps [rollup](https://github.com/rollup/rollup) to 4.22.4 and updates ancestor dependency [vitepress](https://github.com/vuejs/vitepress). These dependencies need to be updated together.


Updates `rollup` from 2.79.1 to 4.22.4
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v2.79.1...v4.22.4)

Updates `vitepress` from 1.0.0-alpha.16 to 1.3.4
- [Release notes](https://github.com/vuejs/vitepress/releases)
- [Changelog](https://github.com/vuejs/vitepress/blob/main/CHANGELOG.md)
- [Commits](vuejs/vitepress@v1.0.0-alpha.16...v1.3.4)

---
updated-dependencies:
- dependency-name: rollup
  dependency-type: indirect
- dependency-name: vitepress
  dependency-type: direct:development
...

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