Fix tests on macOS ARM (#368)

update

Author: rusty1s

torch_sparse/testing.py

@@ -16,8 +16,6 @@
 devices = [torch.device('cpu')]
 if torch.cuda.is_available():
  devices += [torch.device('cuda:0')]
-if torch.backends.mps.is_available():
- devices += [torch.device('mps')]
 
 
 def tensor(x: Any, dtype: torch.dtype, device: torch.device):