More consistent way to add build options modules

[hryx]

In the build system, OptionsSteps are a nice way to pass build variables to Zig code being built. But there is a small incongruity between how you do it for CompileSteps and for Modules.

pub fn build(b: *std.Build) void {
    // Get option values from the CLI and create options module
    const sideways = b.option(bool, "sideways", "you know what this means") orelse false;
    const shared_opts = b.addOptions();
    shared_opts.addOption("sideways", sideways);

    // For CompileStep, use addOptions()
    const exe = b.addExecutable("pigeon", .{});
    exe.addOptions(shared_opts); // <--

    // For Module, pass as a dependency
    const mod = b.addModule("chicken", .{
        .root_source_file = .{},
        .dependencies = &.{ shared_opts.createModule() }, // <--
    });
}

I think there could be a less confusing API. Possibilities:

1. Duplicate the addOptions method to Module.
2. Remove addOptions so that CompileStep and friends instead use exe.addModule("options", my_opts.createModule()), closing the discrepancy.
3. Something else?

[xdBronch]

i believe this can be closed after the modules rework, build options are done by adding it to a compile steps root_module now