zig: update to 0.6.0.

[jailbird777]

Testing the changes

• I tested the changes in this PR: YES

Local build testing

• I built this PR locally for my native architecture, aarch64-glibc
• I built this PR locally for these architectures (if supported. mark crossbuilds):
  • x86_64-musl

[jailbird777]

I included @rXelelo 's change from #59883

[tranzystorekk]

Zig is a sensitive package that I'd like to handle properly myself, e.g. ensure any zig pkgs we already have continue to build successfully.