Update dependency clean-webpack-plugin to v4

Author: renovate-bot

package.json

@@ -24,7 +24,7 @@
         "@becklyn/typescript-error-formatter": "^1.0.4",
         "babel-eslint": "^10.1.0",
         "babel-loader": "^8.1.0",
-        "clean-webpack-plugin": "^3.0.0",
+        "clean-webpack-plugin": "^4.0.0",
         "core-js": "^3.6.5",
         "duplicate-package-checker-webpack-plugin": "^3.0.0",
         "eslint": "^6.8.0",