PYTHON-4463 Add missing data in connection string test (mongodb#1685)

Author: blink1073

test/connection_string/test/valid-warnings.json

@@ -107,7 +107,9 @@
         }
       ],
       "auth": null,
-      "options": null
+      "options": {
+        "authMechanism": "MONGODB-OIDC"
+      }
     }
   ]
 }