gh-151678: Fix a duplicate test_edit_undo_redo in TextTest

A second test_edit_undo_redo silently shadowed the earlier one, so its
edit_canundo()/edit_canredo() coverage was never run.  Rename it to
test_edit_canundo_canredo and move it next to the other edit tests.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: serhiy-storchaka

Lib/test/test_tkinter/test_text.py

@@ -26,29 +26,6 @@ def test_debug(self):
             text.debug(olddebug)
             self.assertEqual(text.debug(), olddebug)
 
-    def test_edit_undo_redo(self):
-        text = self.text
-        text.configure(undo=True)
-
-        self.assertIs(text.edit_canundo(), False)
-        self.assertIs(text.edit_canredo(), False)
-
-        text.insert('1.0', 'spam')
-        self.assertIs(text.edit_canundo(), True)
-        self.assertIs(text.edit_canredo(), False)
-
-        text.edit_undo()
-        self.assertIs(text.edit_canundo(), False)
-        self.assertIs(text.edit_canredo(), True)
-
-        text.edit_redo()
-        self.assertIs(text.edit_canundo(), True)
-        self.assertIs(text.edit_canredo(), False)
-
-        text.edit_reset()
-        self.assertIs(text.edit_canundo(), False)
-        self.assertIs(text.edit_canredo(), False)
-
     def test_index(self):
         text = self.text
         text.insert('1.0', 'Lorem ipsum\ndolor sit amet')
@@ -329,6 +306,29 @@ def test_edit_undo_redo(self):
         text.edit_reset()
         self.assertRaises(TclError, text.edit_undo)
 
+    def test_edit_canundo_canredo(self):
+        text = self.text
+        text.configure(undo=True)
+
+        self.assertIs(text.edit_canundo(), False)
+        self.assertIs(text.edit_canredo(), False)
+
+        text.insert('1.0', 'spam')
+        self.assertIs(text.edit_canundo(), True)
+        self.assertIs(text.edit_canredo(), False)
+
+        text.edit_undo()
+        self.assertIs(text.edit_canundo(), False)
+        self.assertIs(text.edit_canredo(), True)
+
+        text.edit_redo()
+        self.assertIs(text.edit_canundo(), True)
+        self.assertIs(text.edit_canredo(), False)
+
+        text.edit_reset()
+        self.assertIs(text.edit_canundo(), False)
+        self.assertIs(text.edit_canredo(), False)
+
     def test_dump(self):
         text = self.text
         text.insert('1.0', 'hello')