Function reduce_fast

pub fn reduce_fast<C: Config, const D: usize>(
    builder: &mut Builder<C>,
    dim_idx: Var<C::N>,
    dims: &Array<C, DimensionsVariable<C>>,
    curr_height_padded: Var<C::N>,
    opened_values: &Array<C, Array<C, Ext<C::F, C::EF>>>,
) -> Array<C, Felt<C::F>>