[Fix] Allow to create SparseAutoModelForCausalLM with trust_remote_code=True

[dbogunowicz]

Feature Description

Now this executes properly:

from sparseml.transformers import SparseAutoModelForCausalLM
model = SparseAutoModelForCausalLM.from_pretrained("microsoft/Phi-3-mini-128k-instruct",trust_remote_code=True)
print(model.__class__.__name__)
>> 'Phi3ForCausalLM'

The hack was to temporarily rename the class so that the from_pretrained method could properly resolve the "remote code load" logic. The model return by the from_pretrained method is unaffected later on, as it will have the class name of the loaded function (as shown above)

This PR needs to land as well, so that the functionality is fully enabled: neuralmagic/compressed-tensors#104

[anmarques]

I tested w/ microsoft/Phi-3-mini-128k-instruct both original and after SparseML quantization and it workd