remove a debug comment from training

mu_map/training/default.py

@@ -276,7 +276,6 @@ if __name__ == "__main__":
             pin_memory=True,
             num_workers=1,
         )
-        print(f"{split} in dataset {len(dataset)} and in loader {len(data_loader)}")
         data_loaders[split] = data_loader
 
     training = Training(