bpo-40025: Require _generate_next_value_ to be defined before members(GH-19763)

require `_generate_next_value_` to be defined before members
diff --git a/Misc/ACKS b/Misc/ACKS
index 34a6fc4..e85e370 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1217,6 +1217,7 @@
 Bryan Olson
 Grant Olson
 Koray Oner
+Ethan Onstott
 Piet van Oostrum
 Tomas Oppelstrup
 Jason Orendorff