Bump webpack-dev-server from 3.10.3 to 5.2.1

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 3.10.3 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@v3.10.3...v5.2.1)

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

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

Author: dependabot[bot]

packages/dev-server/package.json

@@ -16,7 +16,7 @@
   "bugs": "https://github.com/andywer/webpack-blocks/issues",
   "dependencies": {
     "webpack": "^4.42.1",
-    "webpack-dev-server": "^3.10.3"
+    "webpack-dev-server": "^5.2.1"
   },
   "peerDependencies": {
     "@webpack-blocks/core": "^2.0.0"

packages/sample-app/package.json

@@ -28,6 +28,6 @@
     "webpack": "^4.20.2",
     "webpack-blocks": "^2.1.0",
     "webpack-cli": "^3.1.2",
-    "webpack-dev-server": "^3.1.9"
+    "webpack-dev-server": "^5.2.1"
   }
 }