Update dependency autoprefixer to v10.4.21

Author: pulumi-renovate[bot]

Diff for: aws-ts-nextjs/demoapp/package.json

@@ -14,7 +14,7 @@
     "@types/node": "22.13.5",
     "@types/react": "19.0.10",
     "@types/react-dom": "19.0.4",
-    "autoprefixer": "10.4.20",
+    "autoprefixer": "10.4.21",
     "eslint": "9.21.0",
     "eslint-config-next": "15.2.1",
     "next": "15.2.3",