Bump postcss from 8.3.9 to 8.3.11

Bumps [postcss](https://github.com/postcss/postcss) from 8.3.9 to 8.3.11.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.3.9...8.3.11)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

package.json

@@ -36,7 +36,7 @@
     "expose-loader": "^3.1.0",
     "html-loader": "^2.1.2",
     "html-webpack-plugin": "^5.4.0",
-    "postcss": "^8.3.9",
+    "postcss": "^8.3.11",
     "postcss-loader": "^6.2.0",
     "postcss-preset-env": "^6.7.0",
     "sass": "^1.43.3",