update settings with function to ignore unused settings

src/rendering/vulkan/settings.zig

@@ -7,3 +7,7 @@ pub const khronos_layer_on = true;
 pub const assist_layer_on = true;
 pub const messenger_on = true;
 pub const rt_on = false;
+
+pub fn OnlyIf(comptime setting: bool, t: anytype) t {
+    return if (setting) t else void;
+}