Update Zig bindings to Zig 0.12.0

[lockbox]

The latest tagged zig release is 0.12.0 https://ziglang.org/download/0.12.0/release-notes.html, this pr does a few things:

• updates the zig bindings to be compatible with zig 0.12.0
• cleans up the build.zig code
• makes the zig ci pass
• make unicorn be usable by the Zig Build System

I plan on pushing more cleanup pr's to the zig stuff and make an actual "zig-style" api

[wtdcode]

Here you go!