Add callbacks to train function in W&B sweep (#4742)

* add callbacks to train function in wandb sweep

Fix following https://github.com/ultralytics/yolov5/pull/4688 which modified the function signature to `train`

* Cleanup

Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

utils/loggers/wandb/sweep.py

@@ -9,6 +9,7 @@ sys.path.append(FILE.parents[3].as_posix())  # add utils/ to path
 from train import train, parse_opt
 from utils.general import increment_path
 from utils.torch_utils import select_device
+from utils.callbacks import Callbacks
 
 
 def sweep():
@@ -26,7 +27,7 @@ def sweep():
     device = select_device(opt.device, batch_size=opt.batch_size)
 
     # train
-    train(hyp_dict, opt, device)
+    train(hyp_dict, opt, device, callbacks=Callbacks())
 
 
 if __name__ == "__main__":