Build failure with zig 0.13

[carlocab]

Running zig build fails with the latest release of zig (0.13) with:

❯ zig build
/private/tmp/fastfec-0.2.0/build.zig:43:20: error: member function expected 1 argument(s), found 2
        fastfec_cli.addCSourceFiles(&libSources, &buildOptions);
        ~~~~~~~~~~~^~~~~~~~~~~~~~~~
/opt/homebrew/Cellar/zig/0.13.0/lib/zig/std/Build/Step/Compile.zig:782:5: note: function declared here
pub fn addCSourceFiles(compile: *Compile, options: Module.AddCSourceFilesOptions) void {
~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
referenced by:
    runBuild__anon_8415: /opt/homebrew/Cellar/zig/0.13.0/lib/zig/std/Build.zig:2117:37
    main: /opt/homebrew/Cellar/zig/0.13.0/lib/zig/compiler/build_runner.zig:301:29
    remaining reference traces hidden; use '-freference-trace' to see all reference traces

zig build also broke in 0.11 (see #61, fixed in #62). A longer-term solution may be to use a more stable build system (e.g. standard Makefiles, or CMake).