FIX #17794 changing lang now changes keyboard too

the previous behaviour was confusing: changing the language was
changing the keyboard layout in the UI, but not really changing it.

config/chroot_local-includes/usr/lib/python3/dist-packages/tailsgreeter/ui/region_settings.py

@@ -273,3 +273,4 @@ class KeyboardSettingUI(LocalizationSettingUI):
         self.value = layout
         self.update_value_label()
         self._setting.save(layout, is_default=True)
+        self.apply()