Update requirements.txt for Django version
Update requirements.txt for Django version

Do not allow Django 4.x+ in requirements, until we can look at it when released and do any necessary updates to support it.
gwasser/django-helpdesk,django-helpdesk/django-helpdesk,gwasser/django-helpdesk,django-helpdesk/django-helpdesk,django-helpdesk/django-helpdesk,rossp/django-helpdesk,gwasser/django-helpdesk,rossp/django-helpdesk,rossp/django-helpdesk,django-helpdesk/django-helpdesk,rossp/django-helpdesk,gwasser/django-helpdesk