Unfortunately, this has irreconcilable incompatibilities with previous
versions of zig, due to the build.zig.zon schema changes. Support for
older versions has been dropped.
This works around ziglang/zig#22078 (the ast-check behavior changed
since the last successful CI run). Since we build as part of the job,
this check isn't really necessary anyway, though it certainly is
lighter-weight than trying to compile.
