chore(deps): update pnpm to >=8.6.4

Author: renovate[bot]

packages/mercurius-codegen/package.json

@@ -79,6 +79,6 @@
     "prettier": "^2.8.8"
   },
   "engines": {
-    "pnpm": ">=8.6.3"
+    "pnpm": ">=8.6.4"
   }
 }