Function init_reduce_output 

pub fn init_reduce_output<Run: CubeRuntime>(
    input: &CubeTensor<Run>,
    dim: usize,
    dtypes: &ReduceDtypes,
) -> Option<CubeTensor<Run>>

Creates an empty output tensor with the proper shape and decreasing strides to reduce the given axis of input or return None if axis is out-of-bound.