Use int instead of numbers.integral in docstring (#237)

Author: NicolasHug

src/torchcodec/decoders/_video_decoder.py

@@ -135,7 +135,7 @@ def __getitem__(self, key: Union[numbers.Integral, slice]) -> Tensor:
         """Return frame or frames as tensors, at the given index or range.
 
         Args:
-            key(numbers.Integral or slice): The index or range of frame(s) to retrieve.
+            key(int or slice): The index or range of frame(s) to retrieve.
 
         Returns:
             torch.Tensor: The frame or frames at the given index or range.