[tests] make 2 tests device-agnostic (#9347)

* enabel on xpu

* fix style

tests/models/autoencoders/test_models_vae.py

@@ -1036,9 +1036,9 @@ def test_encode_decode(self):
             "https://huggingface.co/datasets/hf-internal-testing/diffusers-images/resolve/main"
             "/img2img/sketch-mountains-input.jpg"
         ).resize((256, 256))
-        image = torch.from_numpy(np.array(image).transpose(2, 0, 1).astype(np.float32) / 127.5 - 1)[
-            None, :, :, :
-        ].cuda()
+        image = torch.from_numpy(np.array(image).transpose(2, 0, 1).astype(np.float32) / 127.5 - 1)[None, :, :, :].to(
+            torch_device
+        )
 
         latent = vae.encode(image).latent_dist.mean
 
@@ -1079,7 +1079,7 @@ def test_encode_decode_f16(self):
         image = (
             torch.from_numpy(np.array(image).transpose(2, 0, 1).astype(np.float32) / 127.5 - 1)[None, :, :, :]
             .half()
-            .cuda()
+            .to(torch_device)
         )
 
         latent = vae.encode(image).latent_dist.mean