gh-91398: Remove the border around the IDLE Shell sidebar (GH-32363)

It was drawn in the window background color and stood out with dark themes.
(cherry picked from commit 82952e3)

Co-authored-by: BA-24 <65275759+BA-24@users.noreply.github.com>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Author: 2 people

Lib/idlelib/sidebar.py

@@ -453,7 +453,7 @@ def mkcmd(eventname):
         return "break"
 
     def grid(self):
-        self.canvas.grid(row=1, column=0, sticky=tk.NSEW, padx=2, pady=0)
+        self.canvas.grid(row=1, column=0, sticky=tk.NSEW)
 
     def change_callback(self):
         if self.is_shown:

Misc/NEWS.d/next/IDLE/2026-09-15-16-19-25.gh-issue-91398.PBdiDB.rst

@@ -0,0 +1,2 @@
+Remove the border around the IDLE Shell sidebar, which was drawn in the
+window background color and stood out with dark themes.