chore(deps): update dependency postcss to v8.5.4

Author: renovate[bot]

package-lock.json

@@ -164,7 +164,7 @@
     "lint-staged": "13.2.3",
     "npm": "6.14.18",
     "ng-packagr": "12.2.7",
-    "postcss": "8.4.26",
+    "postcss": "8.5.4",
     "prettier": "2.8.8",
     "puppeteer": "17.1.3",
     "rxjs": "7.8.1",