bpo-41841: update idlelib News up to 3.10.0 (GH-30871)

Lib/idlelib/NEWS.txt

@@ -1,8 +1,25 @@
-What's New in IDLE 3.9.z
-(since 3.9.0)
-=========================
+What's New in IDLE 3.9 after 3.9.0
+until 3.9.12, 2022-05-16
+==================================
 
 
+bpo-40128: Mostly fix completions on macOS when not using tcl/tk 8.6.11
+(as with 3.9).
+
+bpo-33962: Move the indent space setting from the Font tab to the new Windows
+tab. Patch by Mark Roseman and Terry Jan Reedy.
+
+bpo-40468: Split the settings dialog General tab into Windows and Shell/ED
+tabs. Move help sources, which extend the Help menu, to the Extensions tab.
+Make space for new options and shorten the dialog. The latter makes the dialog
+better fit small screens.
+
+bpo-41611: Avoid occasional uncaught exceptions and freezing when using
+completions on macOS.
+
+bpo-42225: Document that IDLE can fail on Unix either from misconfigured IP
+masquerade rules or failure displaying complex colored (non-ascii) characters.
+
 bpo-43283: Document why printing to IDLE's Shell is often slower than
 printing to a system terminal and that it can be made faster by
 pre-formatting a single string before printing.
@@ -30,6 +47,12 @@ by using inspect.getdoc.
 bpo-33987: Mostly finish using ttk widgets, mainly for editor,
 settings, and searches.  Some patches by Mark Roseman.
 
+bpo-40511: Stop unnecessary "flashing" when typing opening and closing
+parentheses inside the parentheses of a function call.
+
+bpo-38439: Add a 256×256 pixel IDLE icon to the Windows .ico file. Created by
+Andrew Clover. Remove the low-color gif variations from the .ico file.
+
 bpo-41775: Make 'IDLE Shell' the shell title.
 
 bpo-35764: Rewrite the Calltips doc section.