package manager: `zig fetch --save <url>` overwrites `.lazy` field

[emidoots]

Zig Version

0.12.0-dev.3180+83e578a18

Steps to Reproduce and Observed Behavior

With a build.zig.zon file which contains a lazy dependency like:

    .dependencies = .{
        .glfw = .{
            .url = "https://pkg.machengine.org/glfw/8f7ca982913c0ab64df44d79d6ad2fb592e5ec39.tar.gz",
            .hash = "122085745c053e68fea3772c7239c7c87bcc7f042fa3189592b30e0e39cbb9603d79",
            .lazy = true,
        },
    },

zig fetch --save https://pkg.machengine.org/glfw/98b4bca1542156dcedc6ab87b365a7ac61d1b77b.tar.gz

will remove the .lazy field:

Expected Behavior

The .lazy field should remain in place, only the .url and .hash fields should be overwritten.