Bump webpack-dev-server from 5.2.0 to 5.2.1 in /demos/loading/webpack

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 5.2.0 to 5.2.1.
- [Release notes](https://github.com/webpack/webpack-dev-server/releases)
- [Changelog](https://github.com/webpack/webpack-dev-server/blob/master/CHANGELOG.md)
- [Commits](webpack/webpack-dev-server@v5.2.0...v5.2.1)

---
updated-dependencies:
- dependency-name: webpack-dev-server
  dependency-version: 5.2.1
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

demos/loading/webpack/package.json

@@ -28,7 +28,7 @@
     "typescript": "~5.7.3",
     "webpack": "5.97.1",
     "webpack-cli": "6.0.1",
-    "webpack-dev-server": "5.2.0",
+    "webpack-dev-server": "5.2.1",
     "webpack-merge": "6.0.1"
   }
 }