chore(dev-deps): update dependency postcss to v8.4.23

Author: renovate[bot]

package-lock.json

@@ -83,7 +83,7 @@
     "karma-jasmine": "4.0.2",
     "karma-webpack": "4.0.2",
     "npm-run-all": "4.1.5",
-    "postcss": "8.4.21",
+    "postcss": "8.4.23",
     "postcss-cli": "8.3.1",
     "prettier": "2.7.1",
     "rimraf": "3.0.2",