[matmul code] the `compiled_for_gpu` crates always rebuild

[flying-sheep]

When running cargo run or cargo run --release without changes on my system, the compiled_for_gpu crates always rebuild:

   Compiling compiled_isomorphic v0.1.0 (/home/phil/Dev/Rust-GPU matmul kernel/crates/cpu/compiled_for_gpu/isomorphic)
   Compiling compiled_workgroup_2d v0.1.0 (/home/phil/Dev/Rust-GPU matmul kernel/crates/cpu/compiled_for_gpu/workgroup_2d)
   Compiling compiled_tiling_1d_loop v0.1.0 (/home/phil/Dev/Rust-GPU matmul kernel/crates/cpu/compiled_for_gpu/tiling_1d_loop)
   Compiling compiled_tiling_2d v0.1.0 (/home/phil/Dev/Rust-GPU matmul kernel/crates/cpu/compiled_for_gpu/tiling_2d)
   Compiling compiled_workgroup_256 v0.1.0 (/home/phil/Dev/Rust-GPU matmul kernel/crates/cpu/compiled_for_gpu/workgroup_256)
   Compiling compiled_tiling_1d v0.1.0 (/home/phil/Dev/Rust-GPU matmul kernel/crates/cpu/compiled_for_gpu/tiling_1d)
   Compiling compiled_naive v0.1.0 (/home/phil/Dev/Rust-GPU matmul kernel/crates/cpu/compiled_for_gpu/naive)
    Building [======================>  ] 257/273: compiled_tiling_1d(build), compiled_workgroup_256(build), compiled_naive(build), compiled_tiling_1d_loop(build), compiled_isomorphic(build), compiled_tiling_2d(build), compiled_workgroup_2d(build)                                                                                 

One thing I noticed is that the build scripts println!("Generated shader binary constant…. All others I’ve seen only println!("cargo::… for build variables.

Probably meaningless, I just thought I’d mention it.