build(deps-dev): Bump the vuepress group in /docs with 2 updates

Bumps the vuepress group in /docs with 2 updates: [@vuepress/plugin-google-analytics](https://github.com/vuejs/vuepress/tree/HEAD/packages/@vuepress/plugin-google-analytics) and [@vuepress/plugin-register-components](https://github.com/vuejs/vuepress/tree/HEAD/packages/@vuepress/plugin-register-components).


Updates `@vuepress/plugin-google-analytics` from 2.0.0-rc.12 to 2.0.0-rc.15
- [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/plugin-google-analytics)

Updates `@vuepress/plugin-register-components` from 2.0.0-rc.14 to 2.0.0-rc.15
- [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/plugin-register-components)

---
updated-dependencies:
- dependency-name: "@vuepress/plugin-google-analytics"
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: vuepress
- dependency-name: "@vuepress/plugin-register-components"
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: vuepress
...

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