chore(deps-dev): bump webpack-dev-middleware from 3.7.3 to 5.3.4 in /ui

Bumps [webpack-dev-middleware](https://github.com/webpack/webpack-dev-middleware) from 3.7.3 to 5.3.4.
- [Release notes](https://github.com/webpack/webpack-dev-middleware/releases)
- [Changelog](https://github.com/webpack/webpack-dev-middleware/blob/v5.3.4/CHANGELOG.md)
- [Commits](webpack/webpack-dev-middleware@v3.7.3...v5.3.4)

---
updated-dependencies:
- dependency-name: webpack-dev-middleware
  dependency-type: direct:development
...

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

ui/package.json

@@ -176,7 +176,7 @@
     "terser-webpack-plugin": "^3.0.8",
     "url-loader": "4.1.1",
     "webpack-cli": "^3.3.12",
-    "webpack-dev-middleware": "3.7.3",
+    "webpack-dev-middleware": "5.3.4",
     "webpack-hot-middleware": "^2.25.0",
     "webpack-pwa-manifest": "4.3.0"
   },