Bump @vuepress/plugin-active-header-links

Bumps [@vuepress/plugin-active-header-links](https://github.com/vuejs/vuepress/tree/HEAD/packages/@vuepress/plugin-active-header-links) from 2.0.0-beta.49 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/plugin-active-header-links)

---
updated-dependencies:
- dependency-name: "@vuepress/plugin-active-header-links"
  dependency-version: 2.0.0-rc.0
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

package.json

@@ -12,7 +12,7 @@
     "optimize": "sh ./optimize.sh"
   },
   "devDependencies": {
-    "@vuepress/plugin-active-header-links": "^2.0.0-beta.49",
+    "@vuepress/plugin-active-header-links": "^2.0.0-rc.0",
     "@vuepress/plugin-back-to-top": "^2.0.0-beta.49",
     "cypress": "^13.6.4",
     "vuepress": "^2.0.0-beta.49",