fix(deps): update dependency postcss to v8.4.23

Author: renovate[bot]

package-lock.json

@@ -65,7 +65,7 @@
     "image-minimizer-webpack-plugin": "3.8.2",
     "jest": "26.6.3",
     "mini-css-extract-plugin": "1.6.2",
-    "postcss": "8.4.21",
+    "postcss": "8.4.23",
     "postcss-custom-media": "^9.1.2",
     "postcss-loader": "6.2.1",
     "postcss-rtlcss": "3.7.2",