Loading model from .pth is not supported yet

🐛 Bug

To Reproduce

import torch
from litmodels import save_model, load_model

model = torch.nn.Module()
save_model(model=model, name="skaftenicki/language-model/torch-model")
model_ = load_model(name="skaftenicki/language-model/torch-model")

generates

❯ python main.py 
Uploading files...: 100%|█████████████████| 1/1 [00:01<00:00,  1.73s/it]
Model uploaded successfully. Link to the model: 'https://lightning.ai/skaftenicki/language-model/models/torch-model'
Downloading default: 100%|█████████| 1.32k/1.32k [00:00<00:00, 1.71kB/s]
Traceback (most recent call last):          | 0.00/1.32k [00:00<?, ?B/s]
  File "/home/nsde/Documents/LitModels/main.py", line 6, in <module>
    model_ = load_model(name="skaftenicki/language-model/torch-model")
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nsde/Documents/LitModels/src/litmodels/io/gateway.py", line 166, in load_model
    raise NotImplementedError(f"Loading model from {model_path.suffix} is not supported yet.")
NotImplementedError: Loading model from .pth is not supported yet.

Expected behavior

Code is basically taken from the examples. The problem seems to be that save_model function saves torch models to pth (which are not ScriptModule):
https://github.com/Lightning-AI/LitModels/blob/e9075da71a1cea1ec1d978de3971df937856280f/src/litmodels/io/gateway.py#L94-L96
but not supported in the load_model function.

Environment

• PyTorch Version (e.g., 1.0):
• OS (e.g., Linux):
• How you installed PyTorch (conda, pip, source):
• Build command you used (if compiling from source):
• Python version:
• CUDA/cuDNN version:
• GPU models and configuration:
• Any other relevant information:

Additional context

Start in src/litmodels/io/gateway.py, comparing the save_model handling around lines 94-96 with the load_model failure at line 166. Reproduce the Python example from the issue and trace the .pth path through loading. Done means a model saved by save_model can be loaded without the current NotImplementedError.