Bump vuepress-plugin-search-pro from 2.0.0-rc.0 to 2.0.0-rc.4

Bumps [vuepress-plugin-search-pro](https://github.com/vuepress-theme-hope/vuepress-theme-hope/tree/HEAD/packages/search-pro) from 2.0.0-rc.0 to 2.0.0-rc.4.
- [Release notes](https://github.com/vuepress-theme-hope/vuepress-theme-hope/releases)
- [Changelog](https://github.com/vuepress-theme-hope/vuepress-theme-hope/blob/main/CHANGELOG.md)
- [Commits](https://github.com/vuepress-theme-hope/vuepress-theme-hope/commits/v2.0.0-rc.4/packages/search-pro)

---
updated-dependencies:
- dependency-name: vuepress-plugin-search-pro
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

package.json

@@ -61,7 +61,7 @@
   },
   "optionalDependencies": {
     "vuepress": "^2.0.0-rc.0",
-    "vuepress-plugin-search-pro": "^2.0.0-rc.0",
+    "vuepress-plugin-search-pro": "^2.0.0-rc.4",
     "vuepress-theme-hope": "^2.0.0-rc.1"
   },
   "resolutions": {