Fixed failing GPU test.

ml-agents/mlagents/trainers/tests/torch_entities/test_attention.py

@@ -1,5 +1,5 @@
 import pytest
-from mlagents.torch_utils import torch
+from mlagents.torch_utils import torch, default_device
 import numpy as np
 
 from mlagents.trainers.torch_entities.utils import ModelUtils
@@ -217,7 +217,7 @@ def test_predict_minimum_training():
             argmin = argmin.squeeze()
             argmin = argmin.detach()
         sliced_oh = onehots[:, : num + 1]
-        inp = torch.cat([inp, sliced_oh], dim=2)
+        inp = torch.cat([inp, sliced_oh.to(default_device())], dim=2)
 
         embeddings = entity_embedding(inp, inp)
         masks = get_zero_entities_mask([inp])