Issue #26240: Clean up the subprocess module doc string

Patch by Tim Mitchell.
diff --git a/Misc/ACKS b/Misc/ACKS
index 8c5c0c2..2ba9ea1 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -999,6 +999,7 @@
 Andrii V. Mishkovskyi
 Dom Mitchell
 Dustin J. Mitchell
+Tim Mitchell
 Zubin Mithra
 Florian Mladitsch
 Doug Moen