Fix typo in Lib/idlelib/idle_test/test_parenmatch.py (GH-93332)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Lib/idlelib/idle_test/test_parenmatch.py

@@ -83,12 +83,12 @@ def test_paren_corner(self):
         """
         Test corner cases in flash_paren_event and paren_closed_event.
 
-        These cases force conditional expression and alternate paths.
+        Force execution of conditional expressions and alternate paths.
         """
         text = self.text
         pm = self.get_parenmatch()
 
-        text.insert('insert', '# this is a commen)')
+        text.insert('insert', '# Comment.)')
         pm.paren_closed_event('event')
 
         text.insert('insert', '\ndef')