Update Zig to use the new Writergate version

[IntegratedQuantum]

For reference: ziglang/zig#24329

some commits have been extracted from #1583, but the x86_64 backend has been disabled due to its horrible performance.

Remaining work:

• Wait for official builds on ziglang.org and upload them to our repository
• Add workaround for Fix posix.sendto for Windows ziglang/zig#24466
• Fix TODO comment about ANSI support in stdout
• Check for compile-time performance changes → it went from 13.1 to 11.9 seconds 🎉