dep/cubeb: Add missing oss_i4_v4.c test file

dep/cubeb/cmake/compile_tests/oss_is_v4.c

@@ -0,0 +1,10 @@
+#include <sys/soundcard.h>
+
+#if SOUND_VERSION < 0x040000
+# error "OSSv4 is not available in sys/soundcard.h"
+#endif
+
+int main()
+{
+	return 0;
+}