Smart-Notifier crashes with 'gi.repository.Gtk' object has no attribute 'main'

[Ben Tobin]

Smart-Notifier crashes when started without the --notify argument with the following output:

/usr/share/smart-notifier/smart_notifier/gui.py:23: PyGIWarning: Gtk was imported without specifying a version first. Use gi.require_version('Gtk', '4.0') before import to ensure that the right version gets loaded.
  from gi.repository import Gtk
Traceback (most recent call last):
  File "/usr/bin/smart-notifier", line 14, in <module>
    smart_notifier.gui.service()
  File "/usr/share/smart-notifier/smart_notifier/gui.py", line 52, in service
    Gtk.main()
  File "/usr/lib/python3/dist-packages/gi/overrides/__init__.py", line 32, in __getattr__
    return getattr(self._introspection_module, name)
  File "/usr/lib/python3/dist-packages/gi/module.py", line 123, in __getattr__
    raise AttributeError("%r object has no attribute %r" % (
AttributeError: 'gi.repository.Gtk' object has no attribute 'main'