games/veloren: Update packed_simd_2 crate

It fixes the build with the upcoming rust 1.60.0 update

error message:
error[E0635]: unknown feature `llvm_asm`
   --> /wrkdirs/usr/ports/games/veloren/work/veloren-b5bac97c2e533bc61faf39ab0a43a037aa5a5ccf/cargo-crates/packed_simd_2-0.3.6/src/lib.rs:227:5

Approved by:	portmgr (build fix blanket)