Fix `wandb` integration with `SetFit` model (#30021)

Fix W&B integration with SetFit model
Co-authored-by: PEARCE Timothe <timothe_pearce@ext.connect-tech.sncf>

src/transformers/integrations/integration_utils.py

@@ -753,7 +753,7 @@ class WandbCallback(TrainerCallback):
             combined_dict = {**args.to_dict()}
 
             if hasattr(model, "config") and model.config is not None:
-                model_config = model.config.to_dict()
+                model_config = model.config if isinstance(model.config, dict) else model.config.to_dict()
                 combined_dict = {**model_config, **combined_dict}
             if hasattr(model, "peft_config") and model.peft_config is not None:
                 peft_config = model.peft_config