add: upgrade oas-normalize and use promise-based api (#806)

package.json

@@ -57,7 +57,7 @@
     "@docusaurus/theme-search-algolia": "^2.0.0-beta.3",
     "global": "^4.4.0",
     "import-from": "^3.0.0",
-    "oas-normalize": "^2.3.1",
+    "oas-normalize": "^5.0.1",
     "swagger-inline": "^3.2.2"
   }
 }