gh-113269: IDLE - Fix test_editor hang (macOS) (#113271)

Hangs on installed 3.13.0a2 on macOS Catalina.
Behavior on installed 3.12.1 and 3.11.7 is unknown.

Author: terryjreedy

Lib/idlelib/News3.txt

@@ -4,6 +4,8 @@ Released on 2024-10-xx
 =========================
 
 
+gh-113269: Fix test_editor hang on macOS Catalina.
+
 gh-112939: Fix processing unsaved files when quitting IDLE on macOS.
 Patch by Ronald Oussoren and Christopher Chavez.
 

Lib/idlelib/idle_test/test_editor.py

@@ -95,7 +95,7 @@ def test_tabwidth_8(self):
 def insert(text, string):
     text.delete('1.0', 'end')
     text.insert('end', string)
-    text.update()  # Force update for colorizer to finish.
+    text.update_idletasks()  # Force update for colorizer to finish.
 
 
 class IndentAndNewlineTest(unittest.TestCase):

Misc/NEWS.d/next/IDLE/2023-12-19-00-03-12.gh-issue-113269.lrU-IC.rst

@@ -0,0 +1 @@
+Fix test_editor hang on macOS Catalina.