Implements Pod and Zeroable for AVX512 types that don't require nightly. Additionally allows for the utilization of must_cast_mut and must_cast_slice_mut in const-contexts on Rust 1.83+

Implements Pod and Zeroable for AVX512 types that don't require nightly. Additionally allows for the utilization of must_cast_mut and must_cast_slice_mut in const-contexts on Rust 1.83+ #615