message: Remove Python gradient for ReadVariableOp
diff: @@ -2135,12 +2135,6 @@ class _UnreadVariable(BaseResourceVariable):
  return self._parent_op
  -@ops.RegisterGradient("ReadVariableOp")
  -def _ReadGrad(_, grad):
  - """Gradient for read op."""
  - return grad
  -
  -
  def variable_shape(handle, out_type=dtypes.int32):
  if getattr(handle, "_handle_data",
  None) is None or not handle._handle_data.is_set: # pylint: disable=protected-access
  