chore(test-project): Update to postcss 8.5.6 (#141)

Bumping postcss from 8.5.5 to 8.5.6

Author: Tobbe

__fixtures__/test-project/web/package.json

@@ -24,7 +24,7 @@
     "@types/react": "^18.2.55",
     "@types/react-dom": "^18.2.19",
     "autoprefixer": "^10.4.21",
-    "postcss": "^8.5.5",
+    "postcss": "^8.5.6",
     "postcss-loader": "^8.1.1",
     "tailwindcss": "^3.4.17"
   }