fix(deps): update dependency openapi-backend to v5.9.1

Author: renovate[bot]

packages/api-mock/package.json

@@ -29,7 +29,7 @@
     "cors": "2.8.5",
     "express": "4.18.2",
     "nanoid": "3.3.4",
-    "openapi-backend": "5.8.1",
+    "openapi-backend": "5.9.1",
     "yargs": "17.7.1"
   },
   "devDependencies": {