BREAKING CHANGE: Update dependency copy-webpack-plugin to v6

Author: renovate-bot

package.json

@@ -30,7 +30,7 @@
     "chalk": "2.4.2",
     "cli-table": "0.3.1",
     "connect-history-api-fallback": "1.6.0",
-    "copy-webpack-plugin": "5.1.2",
+    "copy-webpack-plugin": "6.3.1",
     "cosmiconfig": "5.2.1",
     "cross-spawn": "7.0.3",
     "css-loader": "4.3.0",