chore: update loadtest based on 0.5.0-rc.4

tests/default.loadtest.js

@@ -13,7 +13,7 @@ export const options = {
   // Below thresholds are tested against TabbyML/StarCoder-1B served by NVIDIA T4 GPU.
   thresholds: {
     http_req_failed: ['rate<0.01'], // http errors should be less than 1%
-    http_req_duration: ["med<400", "avg<1500", "p(95)<3000"],
+    http_req_duration: ["med<2500", "avg<2200", "p(95)<2500"],
   },
 };