Bump webpack-dev-server from 3.11.2 to 4.6.0 in /frontend

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 3.11.2 to 4.6.0.
- [Release notes](https://github.com/webpack/webpack-dev-server/releases)
- [Changelog](https://github.com/webpack/webpack-dev-server/blob/master/CHANGELOG.md)
- [Commits](webpack/webpack-dev-server@v3.11.2...v4.6.0)

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

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

Author: dependabot[bot]

frontend/package.json

@@ -22,7 +22,7 @@
     "typescript": "^4.5.2",
     "webpack": "^4.44.2",
     "webpack-cli": "^3.3.12",
-    "webpack-dev-server": "^3.11.2"
+    "webpack-dev-server": "^4.6.0"
   },
   "dependencies": {
     "react": "^17.0.2",