remove custom __repr__ from prototype features (#5916)

Author: pmeier

torchvision/prototype/features/_feature.py

@@ -83,6 +83,3 @@ def __torch_function__(
             return cls.new_like(args[0], output, dtype=output.dtype, device=output.device)
         else:
             return output
-
-    def __repr__(self) -> str:
-        return cast(str, torch.Tensor.__repr__(self)).replace("tensor", type(self).__name__)