Avoids warnings:
/home/runner/work/django-scheduler/django-scheduler/schedule/models/events.py:241: RemovedInDjango50Warning: The django.utils.timezone.utc alias is deprecated. Please update your code to use datetime.timezone.utc instead.
Coverage remained the same at 79.958% when pulling 02108a74ae6ecb37d0d7794eb42594655dd3687d on francoisfreitag:utc into 41c1342380a32e56349e6a22f564878950aa161e on llazzaro:develop.
Avoids warnings: /home/runner/work/django-scheduler/django-scheduler/schedule/models/events.py:241: RemovedInDjango50Warning: The django.utils.timezone.utc alias is deprecated. Please update your code to use datetime.timezone.utc instead.