Extend ModularPipeline.save pretrained() to save component model weights in addition to the pipeline…

Extend ModularPipeline.save pretrained() to save component model weights in addition to the pipeline…: a task in HF ML Tasksmith (Harbor dataset). New signature: python def save pretrained( self, save directory: str os.PathLike, safe serialization: bool = True, variant: str None = None, max shard…

The task

**New signature:** ```python def save_pretrained( self, save_directory: str | os.PathLike, safe_serialization: bool = True, variant: str | None = None, max_shard_size: int | str | None = None, push_to_hub: bool = False, **kwargs, # includes overwrite_modular_index, repo_id, ... ) ```

Part of FineEnvs/HF_ML_Tasksmith.