fix numpy decollate multi arrays

Signed-off-by: Arthur Dujardin <arthurdujardin.dev@gmail.com>

Author: arthurdjn

monai/data/utils.py

@@ -647,10 +647,10 @@ def decollate_batch(batch, detach: bool = True, pad=True, fill_value=None):
     if isinstance(batch, np.ndarray):
         if batch.ndim == 0:
             return batch.item()
-        out_list = np.split(batch, batch.shape[0], axis=0)  # type: ignore[assignment]
+        out_list = list(batch)
         if out_list[0].ndim == 0 and detach:
             return [t.item() for t in out_list]
-        return list(out_list)
+        return out_list
 
     b, non_iterable, deco = _non_zipping_check(batch, detach, pad, fill_value)
     if b <= 0:  # all non-iterable, single item "batch"? {"image": 1, "label": 1}