Bump postcss from 8.3.6 to 8.3.11 (#4191)

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

package.json

@@ -344,7 +344,7 @@
     "node-loader": "^1.0.3",
     "nodemon": "^2.0.14",
     "playwright": "^1.15.2",
-    "postcss": "^8.3.6",
+    "postcss": "^8.3.11",
     "postcss-loader": "4.3.0",
     "postinstall-postinstall": "^2.1.0",
     "progress-bar-webpack-plugin": "^2.1.0",