Update to Django 4.2

- fix deprecation warnings
- update dependencies

gnuviechadmin/contact_form/forms.py

@@ -7,6 +7,7 @@ from __future__ import absolute_import, unicode_literals
 from crispy_forms.helper import FormHelper
 from crispy_forms.layout import Submit
 from django import forms
+from django.apps import apps
 from django.conf import settings
 from django.contrib.sites.models import Site
 from django.contrib.sites.requests import RequestSite
@@ -41,7 +42,7 @@ class ContactForm(forms.Form):
     def get_context(self):
         if not self.is_valid():
             raise ValueError("Cannot generate context from invalid contact form")
-        if Site._meta.installed:
+        if apps.is_installed("django.contrib.sites"):
             site = Site.objects.get_current()
         else:
             site = RequestSite(self.request)