fix build artifacts

scripts/build_artifacts.lua

@@ -43,6 +43,7 @@ function main()
            assert(file == file:lower(), "%s must be lower case!", file)
            local packagedir = path.directory(file)
            local packagename = path.filename(packagedir)
+           if #path.filename(path.directory(packagedir)) == 1 then
                local instance = package.load_from_repository(packagename, nil, packagedir, file)
                if instance and packages.is_supported(instance, "windows")
                   and (instance.is_headeronly and not instance:is_headeronly()) then
@@ -56,3 +57,4 @@ function main()
             end
        end
     end
+end