[!HOTFIX] Handle error when saving model checkpoints and artifacts

[hglee98]

Description

A critical issue is identified when training models containing re-parametrizable blocks. This issue occurs because the original model structure changes during the checkpoint saving process. To resolve this, I implement a deepcopy function that runs before saving the model artifacts.

Change(s)

• Add deepcopy function before conducting reparam

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[illian01]

LGTM!