Download Zig toolchains by rewriting the URL as follows:
https://ziglang.org/builds/$FILE -> https://zig.vortan.dev/zig/$FILE
A Zig index.json file is available, mirroring the official ziglang.org/download/index.json - but with downloads pointing to this mirror, and with nominated zig versions added.
Note: .tar.gz, .zip, and .minisig signatures are available for download. Signatures can also be downloaded from ziglang.org for verification purposes.