Fix PyTorch 2.6+ weights_only=True unpickling error for XttsConfig

app.py

@@ -61,6 +61,7 @@ config = XttsConfig()
 config.load_json(os.path.join(model_path, "config.json"))
 
 model = Xtts.init_from_config(config)
+torch.serialization.add_safe_globals([XttsConfig])
 model.load_checkpoint(
     config,
     checkpoint_path=os.path.join(model_path, "model.pth"),