[VITS] Fix nightly tests (#25986)

* fix tokenizer

* make bs even

* fix multi gpu test

* style

* model forward

* fix torch import

* revert tok pin

tests/models/vits/test_modeling_vits.py

@@ -27,6 +27,7 @@
     is_flaky,
     is_torch_available,
     require_torch,
+    require_torch_multi_gpu,
     slow,
     torch_device,
 )
@@ -177,6 +178,30 @@ def test_model_forward(self):
         config_and_inputs = self.model_tester.prepare_config_and_inputs()
         self.model_tester.create_and_check_model_forward(*config_and_inputs)
 
+    @require_torch_multi_gpu
+    # override to force all elements of the batch to have the same sequence length across GPUs
+    def test_multi_gpu_data_parallel_forward(self):
+        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
+        config.use_stochastic_duration_prediction = False
+
+        # move input tensors to cuda:O
+        for key, value in inputs_dict.items():
+            if torch.is_tensor(value):
+                # make all elements of the batch the same -> ensures the output seq lengths are the same for DP
+                value[1:] = value[0]
+                inputs_dict[key] = value.to(0)
+
+        for model_class in self.all_model_classes:
+            model = model_class(config=config)
+            model.to(0)
+            model.eval()
+
+            # Wrap model in nn.DataParallel
+            model = torch.nn.DataParallel(model)
+            set_seed(555)
+            with torch.no_grad():
+                _ = model(**self._prepare_for_class(inputs_dict, model_class)).waveform
+
     @unittest.skip("VITS is not deterministic")
     def test_determinism(self):
         pass