gh-154357: Tolerate additional focus events in test_focus

All focus events seen by bindings are generated by Tk itself: one in
focus_force(), and one more when the real X focus event arrives and the
window manager had taken the focus away in between.  Only the first
event, generated by focus_force(), is checked.

Author: serhiy-storchaka

Lib/test/test_tkinter/test_misc.py

@@ -1373,7 +1373,9 @@ def test_focus(self):
 
         f.focus_force()
         self.root.update()
-        self.assertEqual(len(events), 1, events)
+        # The window manager can take the focus away and give it back,
+        # which makes Tk generate additional focus events.
+        self.assertGreaterEqual(len(events), 1, events)
         e = events[0]
         self.assertIs(e.type, tkinter.EventType.FocusIn)
         self.assertIs(e.widget, f)