midiscripttest: add spdx info

Author: mfisher31

test/scripting/midiscripttest.cpp

@@ -1,3 +1,6 @@
+// Copyright 2023 Kushview, LLC <info@kushview.net>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 #include <boost/test/unit_test.hpp>
 #include <boost/test/data/test_case.hpp>
 #include "luatest.hpp"