bpo-37309: Update IDLE NEWS.txt (GH-20356)

(cherry picked from commit 16ef3241939a3a64a447e5d7aabaf2e29deca621)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt
index b112e8e..709008f 100644
--- a/Lib/idlelib/NEWS.txt
+++ b/Lib/idlelib/NEWS.txt
@@ -4,6 +4,7 @@
 
 
 bpo-40723: Make test_idle pass when run after import.
+Patch by Florian Dahlitz.
 
 bpo-38689: IDLE will no longer freeze when inspect.signature fails
 when fetching a calltip.