add deallocate pipeline output optimization (#8279) (#8318)

* add deallocate pipeline output optimization

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Signed-off-by: Jimmy Zhang <jiemingz@nvidia.com>
Co-authored-by: JimmyZhang12 <67203904+JimmyZhang12@users.noreply.github.com>
Co-authored-by: Jimmy Zhang <jiemingz@nvidia.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Signed-off-by: Michal Futrega <mfutrega@nvidia.com>

nemo/collections/nlp/models/language_modeling/megatron_base_model.py

@@ -475,6 +475,7 @@ def build_transformer_config(self) -> TransformerConfig:
             'recompute_num_layers': recompute_num_layers,
             'distribute_saved_activations': False,  # not currently used in NeMo
             'fp8': None,
+            'deallocate_pipeline_outputs': True,
         }
 
         # populate the transformer config dict