chore(deps-dev): bump mini-css-extract-plugin from 2.8.1 to 2.9.0

Bumps [mini-css-extract-plugin](https://github.com/webpack-contrib/mini-css-extract-plugin) from 2.8.1 to 2.9.0.
- [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@v2.8.1...v2.9.0)

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

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

package.json

@@ -162,7 +162,7 @@
     "license-checker": "^25.0.0",
     "lint-staged": "^15.2.2",
     "local-web-server": "^5.3.3",
-    "mini-css-extract-plugin": "^2.8.1",
+    "mini-css-extract-plugin": "^2.9.0",
     "npm-audit-ci-wrapper": "^3.0.2",
     "npm-run-all": "^4.1.5",
     "oauth2-server": "^2.4.1",