onnxruntime

4fe59c8b - delete model_copy to save memory allocated in forward call (#7832)

delete model_copy to save memory allocated in forward call (#7832) * delete model copy * add flag * address comments * address flag comment Co-authored-by: root <root@OrtTrainingDev0.af05slrtruoetgaxwwjv5nsq5e.px.internal.cloudapp.net>