Add missing 'Averses faibles' and 'Ciel clair' weather classes

[f-laurens]

Avoid nabweatherd crash because of missing weather classes (new Météo France classes?):

see: https://www.tagtagtag.fr/forum/showthread.php?tid=528&pid=3111#pid3111 :

2025-04-22 13:00:28,820 [WARNING] nabweatherd: unexpected weather class: Averses faibles
2025-04-22 13:00:28,822 [WARNING] nabweatherd: unexpected weather class: Averses faibles
2025-04-22 13:00:28,864 [CRITICAL] nabweatherd: Unhandled error: Traceback (most recent call last):
  File "/home/pi/pynab/nabcommon/nabservice.py", line 202, in main
    service.run()
  File "/home/pi/pynab/nabcommon/nabservice.py", line 133, in run
    raise ex
  File "/home/pi/pynab/nabcommon/nabservice.py", line 329, in service_loop
    await self.perform(
  File "/home/pi/pynab/nabweatherd/nabweatherd.py", line 240, in perform
    await NabInfoService.perform(self, expiration, args, config)
  File "/home/pi/pynab/nabcommon/nabservice.py", line 468, in perform
    info_animation = self.get_animation(info_data)
  File "/home/pi/pynab/nabweatherd/nabweatherd.py", line 493, in get_animation
    (weather_class, info_animation) = NabWeatherd.WEATHER_CLASSES[
KeyError: None

see: https://www.tagtagtag.fr/forum/showthread.php?tid=528&pid=3113#pid3113 :

2025-04-24 20:35:47,376 [WARNING] nabweatherd: unexpected weather class: Ciel clair
2025-04-24 20:35:47,658 [WARNING] nabweatherd: unexpected weather class: Ciel clair
2025-04-24 20:35:47,683 [CRITICAL] nabweatherd: Unhandled error: Traceback (most recent call last):
  File "/opt/pynab/nabcommon/nabservice.py", line 202, in main
    service.run()
  File "/opt/pynab/nabcommon/nabservice.py", line 133, in run
    raise ex
  File "/opt/pynab/nabcommon/nabservice.py", line 332, in service_loop
    config,
  File "/opt/pynab/nabweatherd/nabweatherd.py", line 265, in perform
    await self._do_perform_additional(config, weather_forecast)
  File "/opt/pynab/nabweatherd/nabweatherd.py", line 578, in _do_perform_additional
    await self.perform_additional(expiration, type, info_data, config)
  File "/opt/pynab/nabweatherd/nabweatherd.py", line 542, in perform_additional
    info_data["tomorrow_forecast_weather_class"]
KeyError: None