Fix StoppingCriteria ABC signature (#12918)

Change `score` -> `scores` because the argument is not positional-only, so you need consistently named parameters for the subclasses. The subclasses appear to favor `scores` over `score`.

src/transformers/generation_stopping_criteria.py

@@ -35,7 +35,7 @@ class StoppingCriteria(ABC):
     """Abstract base class for all stopping criteria that can be applied during generation."""
 
     @add_start_docstrings(STOPPING_CRITERIA_INPUTS_DOCSTRING)
-    def __call__(self, input_ids: torch.LongTensor, score: torch.FloatTensor, **kwargs) -> bool:
+    def __call__(self, input_ids: torch.LongTensor, scores: torch.FloatTensor, **kwargs) -> bool:
         raise NotImplementedError("StoppingCriteria needs to be subclassed")