package.json: update webpack-cli to v6.0.1

Update webpack-cli from v5.1.4 to v6.0.1. This is compatible with
webpack v5 and the minimum required Node.js version is 18.12.0.

See: https://github.com/webpack/webpack-cli/blob/master/CHANGELOG.md

Author: alanorth

package-lock.json

@@ -238,7 +238,7 @@
     "ts-node": "^8.10.2",
     "typescript": "~5.4.5",
     "webpack": "^5.54.0",
-    "webpack-cli": "^5.1.4",
+    "webpack-cli": "^6.0.1",
     "webpack-dev-server": "^5.2.2"
   }
 }