Bump postcss from 8.3.11 to 8.4.5 (#4560)

Bumps [postcss](https://github.com/postcss/postcss) from 8.3.11 to 8.4.5.
- [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/8.3.11...8.4.5)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -360,7 +360,7 @@
     "node-loader": "^1.0.3",
     "nodemon": "^2.0.14",
     "playwright": "^1.17.1",
-    "postcss": "^8.3.11",
+    "postcss": "^8.4.5",
     "postcss-loader": "4.3.0",
     "postinstall-postinstall": "^2.1.0",
     "progress-bar-webpack-plugin": "^2.1.0",