sim/legacy: remove

that crazy tangle of legacy code evolved over 2+
years into the beast it is today.
but it has no relevance in the GPU-enabled world of today,
particularly one with more rigid Material abstractions.

good things come to an end. i'll try not to be too sentimental.

crates/coremem/src/sim/mod.rs

@@ -9,7 +9,6 @@ use rayon::prelude::*;
 use serde::{Serialize, Deserialize};
 use std::iter::Sum;
 
-pub mod legacy;
 pub mod spirv;
 pub mod units;