[3.13] gh-128846: Make tkinter tests robust against Tcl/Tk 9.0 (GH-153484)

Backport the test-only parts of the Tcl/Tk 8.7/9.0/9.1 test adaptations so
that test_tkinter and test_ttk pass when Python 3.13 is built against
Tcl/Tk 9.0 (for example the Homebrew build used on macOS), while still
passing against the Tcl/Tk 8.6 that 3.13 ships.

Combines the test changes from:

* gh-124111: Update tkinter for compatibility with Tcl/Tk 9.0.0 (GH-124156)
* gh-124111: test macOS CI with Tk 9 (GH-137424)
* gh-145736: Fix Tkinter tests for Tk 8.7, 9.0 and 9.1 (GH-145738)

The corresponding non-test changes (Modules/_tkinter.c, Lib/tkinter/ttk.py,
PCbuild and CI configuration) are not backported.

Author: serhiy-storchaka

Lib/test/test_tkinter/test_misc.py

@@ -110,9 +110,10 @@ def test_tk_busy(self):
         f.tk_busy_forget()
         self.assertFalse(f.tk_busy_status())
         self.assertFalse(f.tk_busy_current())
-        with self.assertRaisesRegex(TclError, "can't find busy window"):
+        errmsg = r"can(no|')t find busy window.*"
+        with self.assertRaisesRegex(TclError, errmsg):
             f.tk_busy_configure()
-        with self.assertRaisesRegex(TclError, "can't find busy window"):
+        with self.assertRaisesRegex(TclError, errmsg):
             f.tk_busy_forget()
 
     @requires_tk(8, 6, 6)
@@ -131,7 +132,8 @@ def test_tk_busy_with_cursor(self):
         self.assertEqual(f.tk_busy_configure('cursor')[4], 'heart')
 
         f.tk_busy_forget()
-        with self.assertRaisesRegex(TclError, "can't find busy window"):
+        errmsg = r"can(no|')t find busy window.*"
+        with self.assertRaisesRegex(TclError, errmsg):
             f.tk_busy_cget('cursor')
 
     def test_tk_setPalette(self):