Bump mini-css-extract-plugin in /build-monitor-plugin

Bumps [mini-css-extract-plugin](https://github.com/webpack-contrib/mini-css-extract-plugin) from 2.8.0 to 2.8.1.
- [Release notes](https://github.com/webpack-contrib/mini-css-extract-plugin/releases)
- [Changelog](https://github.com/webpack-contrib/mini-css-extract-plugin/blob/master/CHANGELOG.md)
- [Commits](webpack-contrib/mini-css-extract-plugin@v2.8.0...v2.8.1)

---
updated-dependencies:
- dependency-name: mini-css-extract-plugin
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

build-monitor-plugin/package.json

@@ -27,7 +27,7 @@
     "karma-junit-reporter": "2.0.1",
     "karma-phantomjs-launcher": "1.0.4",
     "less-loader": "12.2.0",
-    "mini-css-extract-plugin": "2.8.0",
+    "mini-css-extract-plugin": "2.8.1",
     "style-loader": "3.3.4",
     "webpack": "5.90.3",
     "webpack-cli": "5.1.4",