keras/src/ops/numpy.py/Std/compute_output_spec
class Std:    def compute_output_spec(self, x):
        output_dtype = backend.standardize_dtype(x.dtype)
        if "int" in output_dtype or output_dtype == "bool":
            output_dtype = backend.floatx()
        return KerasTensor(
            reduce_shape(x.shape, axis=self.axis, keepdims=self.keepdims),
            dtype=output_dtype,
        )