Update dependency copy-webpack-plugin to ^5.0.4

Author: renovate-bot

package-lock.json

@@ -28,7 +28,7 @@
     "@babel/preset-env": "^7.4.5",
     "babel-loader": "^8.0.6",
     "clean-webpack-plugin": "^3.0.0",
-    "copy-webpack-plugin": "^5.0.3",
+    "copy-webpack-plugin": "^5.0.4",
     "css-loader": "^2.1.1",
     "grafana-sdk-mocks": "github:grafana/grafana-sdk-mocks",
     "style-loader": "^0.23.1",