Update src/cloudai/systems/kubernetes/kubernetes_system.py

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

Author: amaslenn

src/cloudai/systems/kubernetes/kubernetes_system.py

@@ -497,7 +497,7 @@ def _delete_dynamo_graph_deployment(self, job_name: str) -> None:
         if result.returncode != 0:
             logging.debug(f"Failed to delete DynamoGraphDeployment: {result.stderr}")
 
-        if self._port_forward_process and self._port_forward_process.poll():
+        if self._port_forward_process and self._port_forward_process.poll() is None:
             self._port_forward_process.kill()
         self._port_forward_process = None