Bump webpack-merge from 5.3.0 to 5.4.0 (#15166)

Bumps [webpack-merge](https://github.com/survivejs/webpack-merge) from 5.3.0 to 5.4.0.
- [Release notes](https://github.com/survivejs/webpack-merge/releases)
- [Changelog](https://github.com/survivejs/webpack-merge/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/survivejs/webpack-merge/compare/v5.3.0...v5.4.0)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -166,7 +166,7 @@
     "webpack-assets-manifest": "^3.1.1",
     "webpack-bundle-analyzer": "^4.1.0",
     "webpack-cli": "^3.3.12",
-    "webpack-merge": "^5.3.0",
+    "webpack-merge": "^5.4.0",
     "wicg-inert": "^3.1.0"
   },
   "devDependencies": {