chg: passing through trust_remote_code (#778)

## What does this PR do?

**Type of change:** ? <!-- Use one of the following: Bug fix, new
feature, new example, new tests, documentation. --> Bug fix

**Overview:** 

Passing `trust_remote_code` all the way through during export and
import. This is needed since `DeepSeek` will error out if
`trust_remote_code=True` but `Nemotron-H` will error out if
`trust_remote_code=False`

## Usage
<!-- You can potentially add a usage example below. -->

```python
# Add a code snippet demonstrating how to use this
```

## Testing
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## Before your PR is "*Ready for review*"
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- **Make sure you read and follow [Contributor
guidelines](https://github.com/NVIDIA/Model-Optimizer/blob/main/CONTRIBUTING.md)**
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- **Is this change backward compatible?**: Yes/No <!--- If No, explain
why. -->
- **Did you write any new necessary tests?**: Yes/No
- **Did you add or update any necessary documentation?**: Yes/No
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[Changelog](https://github.com/NVIDIA/Model-Optimizer/blob/main/CHANGELOG.rst)?**:
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## Additional Information
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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Bug Fixes**
* Updated default `trust_remote_code` parameter from `True` to `False`
in GPT model export and import functionality.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: Chenhan Yu <chenhany@nvidia.com>

Author: ChenhanYu

modelopt/torch/export/plugins/megatron_importer.py

@@ -75,7 +75,7 @@ def __init__(
         workspace_dir: str | None = None,
         dtype=torch.bfloat16,
         dequantize: bool = True,
-        trust_remote_code: bool = False,
+        trust_remote_code: bool = True,
         verbose: bool = False,
         moe_router_dtype: torch.dtype | None = None,
     ):

modelopt/torch/export/unified_export_megatron.py

@@ -137,7 +137,7 @@ def __init__(
         pretrained_model_name_or_path: str | os.PathLike | None = None,
         export_extra_modules: bool = False,
         dtype=torch.bfloat16,
-        trust_remote_code: bool = True,
+        trust_remote_code: bool = False,
         moe_router_dtype: torch.dtype | None = None,
     ):
         """Create a GPTModel exporter instance."""
@@ -1205,6 +1205,7 @@ def export_mcore_gpt_to_hf(
     export_extra_modules: bool = False,
     dtype: torch.dtype = torch.bfloat16,
     export_dir: Path | str = tempfile.gettempdir(),
+    trust_remote_code: bool = False,
     moe_router_dtype: torch.dtype | None = None,
 ):
     """Export Megatron Core GPTModel to unified checkpoint and save to export_dir.
@@ -1225,6 +1226,7 @@ def export_mcore_gpt_to_hf(
         pretrained_model_name_or_path,
         export_extra_modules=export_extra_modules,
         dtype=dtype,
+        trust_remote_code=trust_remote_code,
         moe_router_dtype=moe_router_dtype,
     )
     exporter.save_pretrained(export_dir, pretrained_model_name_or_path)
@@ -1235,6 +1237,7 @@ def import_mcore_gpt_from_hf(
     pretrained_model_path: str,
     workspace_dir: str | None = None,
     dtype: torch.dtype = torch.bfloat16,
+    trust_remote_code: bool = False,
     moe_router_dtype: torch.dtype | None = None,
 ):
     """Import GPTModel state_dict from supported HuggingFace pretrained model path.
@@ -1243,13 +1246,17 @@ def import_mcore_gpt_from_hf(
         model: The Megatron Core GPTModel instance.
         pretrained_model_path: A path to a *directory* containing model weights saved using
             [`~PreTrainedModel.save_pretrained`], e.g., `./my_model_directory/`.
+        workspace_dir: The directory to save the workspace.
         dtype: The weights data type to import.
+        trust_remote_code: If True, this allows importing from a wider range of sources.
+        moe_router_dtype: The data type to import the moe router weights.
     """
     importer = GPTModelImporter(
         model,
         pretrained_model_path,
         workspace_dir=workspace_dir,
         dtype=dtype,
+        trust_remote_code=trust_remote_code,
         moe_router_dtype=moe_router_dtype,
     )
     importer._import_state_dict()