Bump postcss from 8.4.21 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.21 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.21...8.4.31)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -98,7 +98,7 @@
     "karma-jasmine-html-reporter": "2.0.0",
     "less-vars-to-js": "1.3.0",
     "ng-mocks": "14.6.0",
-    "postcss": "8.4.21",
+    "postcss": "8.4.31",
     "prettier": "2.8.3",
     "prettier-eslint": "15.0.1",
     "tailwindcss": "3.2.4",