gn: Remove stray comma in BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 4603cac..3449410 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -114,7 +114,7 @@
       }
     }
     if (is_mac) {
-      libs = [ "CoreFoundation.framework" ],
+      libs = [ "CoreFoundation.framework" ]
     }
     public_deps = [
       "$vulkan_headers_dir:vulkan_headers",