Add support for unarchiving .zip archives

[kylewlacy]

The unarchive recipe (e.g. std.download({ ... }).unarchive("tar", "gzip")) supports multiple compression formats, but currently only supports tar archives. Zip archives are also pretty common, so we should update the recipe to also support zip as an archive type

const source = std
  .download({
    url: "https://github.com/brioche-dev/brioche/archive/refs/tags/v0.1.1.zip",
    hash: std.sha256sum("1e98a694fe530de5d641ecfa03c0f2f61ba7eba020866a1876ab2c4eaffb1525"),
  })
  .unarchive("zip");

Zip files can themselves be compressed, so there isn't an extra layer of decompression to worry about like you often see with .tar files. In other words, unarchiving a zip file will usually not specify a compression format. However, for consistency, it might still make sense to allow specifying a decompression format, even though I wouldn't expect it to be used in practice