Fixed #18150: duplicate test inside TestSingleDispatch

Thanks to Vajrasky Kok for the patch
diff --git a/Misc/ACKS b/Misc/ACKS
index 3ce5cd2..754500d 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -666,6 +666,7 @@
 Greg Kochanski
 Damon Kohler
 Marko Kohtala
+Vajrasky Kok
 Guido Kollerie
 Jacek Konieczny
 Марк Коренберг