Update modal.json

One-off change to address https://t.corp.amazon.com/V1020690757/communication.

modal.json

@@ -284,6 +284,12 @@
                 "instanceType": "ml.p4de.24xlarge",
                 "numGpu": 8,
                 "containerStartupHealthCheckTimeout": 900
+            },
+            {
+                "id": "lmsys/vicuna-33b-v1.3",
+                "instanceType": "ml.p4de.24xlarge",
+                "numGpu": 4,
+                "containerStartupHealthCheckTimeout": 900
             }
         ]
     },