fix wrong rg (#42324)

Author: PratibhaShrivastav18

sdk/ml/azure-ai-ml/azure/ai/ml/_ml_client.py

@@ -625,7 +625,7 @@ def __init__(
         self._local_endpoint_helper = _LocalEndpointHelper(requests_pipeline=self._requests_pipeline)
         self._local_deployment_helper = _LocalDeploymentHelper(self._operation_container)
         self._online_endpoints = OnlineEndpointOperations(
-            self._operation_scope,
+            self._ws_operation_scope if registry_reference else self._operation_scope,
             self._operation_config,
             self._service_client_02_2022_preview,
             self._operation_container,