build(deps-dev): bump @vuepress/plugin-prismjs

Bumps [@vuepress/plugin-prismjs](https://github.com/vuepress/vuepress-next) from 2.0.0-rc.120 to 2.0.0-rc.121.
- [Release notes](https://github.com/vuepress/vuepress-next/releases)
- [Changelog](https://github.com/vuepress/core/blob/main/CHANGELOG.md)
- [Commits](https://github.com/vuepress/vuepress-next/commits)

---
updated-dependencies:
- dependency-name: "@vuepress/plugin-prismjs"
  dependency-version: 2.0.0-rc.121
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package.json

@@ -83,7 +83,7 @@
     "@vuepress/plugin-copy-code": "^2.0.0-rc.120",
     "@vuepress/plugin-google-analytics": "^2.0.0-rc.118",
     "@vuepress/plugin-markdown-include": "2.0.0-rc.120",
-    "@vuepress/plugin-prismjs": "^2.0.0-rc.120",
+    "@vuepress/plugin-prismjs": "^2.0.0-rc.121",
     "@vuepress/plugin-register-components": "^2.0.0-rc.118",
     "@vuepress/plugin-search": "^2.0.0-rc.118",
     "@vuepress/theme-default": "^2.0.0-rc.118",