chore: update webpack and copy-webpack-plugin to fix serialize-javascript vulnerability (#4959)

This PR updates `copy-webpack-plugin` to `^14.0.0` and `webpack` to
`^5.105.4` in `gcp/website/frontend3`. These updates resolve a
high-severity security vulnerability in the transitive dependency
`serialize-javascript` (reported in GHSA-5c6j-r48x-rmvq).

By updating these direct dependencies, `serialize-javascript` is
upgraded from `6.0.2` to `7.0.4`, which contains the necessary security
fixes.

Author: cuixq

gcp/website/frontend3/package.json

@@ -18,15 +18,15 @@
     "lit": "3.3.2"
   },
   "devDependencies": {
-    "copy-webpack-plugin": "^13.0.0",
+    "copy-webpack-plugin": "^14.0.0",
     "css-loader": "^7.1.3",
     "html-webpack-plugin": "^5.6.6",
     "mini-css-extract-plugin": "^2.10.0",
     "raw-loader": "^4.0.2",
     "sass": "^1.97.3",
     "sass-loader": "^16.0.0",
     "style-loader": "^4.0.0",
-    "webpack": "^5.104.1",
+    "webpack": "^5.105.4",
     "webpack-bundle-analyzer": "^5.0.0",
     "webpack-cli": "^6.0.0",
     "webpack-dev-server": "^5.2.3"