Bump webpack-cli from 3.3.12 to 4.9.2 in /frontend

Bumps [webpack-cli](https://github.com/webpack/webpack-cli) from 3.3.12 to 4.9.2.
- [Release notes](https://github.com/webpack/webpack-cli/releases)
- [Changelog](https://github.com/webpack/webpack-cli/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack/webpack-cli/compare/[email protected])

---
updated-dependencies:
- dependency-name: webpack-cli
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

frontend/package.json

@@ -21,7 +21,7 @@
     "ts-loader": "^7.0.5",
     "typescript": "^4.5.4",
     "webpack": "^4.44.2",
-    "webpack-cli": "^3.3.12",
+    "webpack-cli": "^4.9.2",
     "webpack-dev-server": "^4.7.3"
   },
   "dependencies": {