disable failing standalone test on windows

See tracking issue #14800

test/standalone/mix_c_files/build.zig

@@ -4,6 +4,11 @@ pub fn build(b: *std.Build) void {
     const test_step = b.step("test", "Test it");
     b.default_step = test_step;
 
+    if (@import("builtin").os.tag == .windows) {
+        // https://github.com/ziglang/zig/issues/14800
+        return;
+    }
+
     add(b, test_step, .Debug);
     add(b, test_step, .ReleaseFast);
     add(b, test_step, .ReleaseSmall);
@@ -18,7 +23,6 @@ fn add(b: *std.Build, test_step: *std.Build.Step, optimize: std.builtin.Optimize
     });
     exe.addCSourceFile("test.c", &[_][]const u8{"-std=c11"});
     exe.linkLibC();
-    b.default_step.dependOn(&exe.step);
 
     const run_cmd = b.addRunArtifact(exe);
     run_cmd.skip_foreign_checks = true;