Issue #21860: Correct docstrings of FileIO.seek() and FileIO.truncate() methods.

Patch by Terry Chia.
diff --git a/Misc/ACKS b/Misc/ACKS
index 4a69dfe..1cd18f4 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -237,6 +237,7 @@
 Jerry Chen
 Michael Chermside
 Ingrid Cheung
+Terry Chia
 Albert Chin-A-Young
 Adal Chiriliuc
 Matt Chisholm