Function set1_gadget 

pub fn set1_gadget<W>() -> LogicGadget<W>
where
    W: Clone + Default + From<i32>,

Create a SET1 gadget (constant true).

1-variable SpinGlass that prefers config 1 (spin +1 in Rust convention). h = [-1] (negated from Julia’s [1] to account for different spin convention)