Bump webpack-sources from 2.3.1 to 3.2.0

Bumps [webpack-sources](https://github.com/webpack/webpack-sources) from 2.3.1 to 3.2.0.
- [Release notes](https://github.com/webpack/webpack-sources/releases)
- [Commits](https://github.com/webpack/webpack-sources/compare/v2.3.1...v3.2.0)

---
updated-dependencies:
- dependency-name: webpack-sources
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

package.json

@@ -110,7 +110,7 @@
     "webpack-cli": "^4.5.0",
     "webpack-dev-middleware": "^5.0.0",
     "webpack-dev-server": "^4.0.0-beta.2",
-    "webpack-sources": "^2.2.0",
+    "webpack-sources": "^3.2.0",
     "worker-loader": "^3.0.8",
     "yargs": "^17.0.0"
   },