[NVIDIA-IMEX] Update the fake IPs as per cookbook

Author: Himani Anil Deshpande

tests/integration-tests/tests/ultraserver/test_gb200.py

@@ -30,7 +30,7 @@
 
 # We use placeholder IPs just to get IMEX started.
 # These values are hardwired in the cookbook.
-FAKE_IPS = ["172.31.51.93", "172.31.48.43"]
+FAKE_IPS = ["0.0.0.0"] * 9
 
 
 def submit_job_imex_status(rce: RemoteCommandExecutor, queue: str, max_nodes: int = 1):