Bump webpack-dev-server from 2.4.4 to 5.2.1 in /solvebio/contrib/dash/js

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 2.4.4 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@v2.4.4...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]

solvebio/contrib/dash/js/package.json

@@ -24,7 +24,7 @@
     "sass-loader": "^6.0.3",
     "style-loader": "^0.16.1",
     "webpack": "^2.4.1",
-    "webpack-dev-server": "^2.4.4"
+    "webpack-dev-server": "^5.2.1"
   },
   "dependencies": {
     "babel-loader": "^7.0.0",