Change app import for Django 4

Django 4.1 deprecated the default_app_config option that was used
previously to install the cantusdata app. This app is now installed using
a dotted path in the settings.py file.

Django 4.1 also added a new positional argument to post_delete signals,
which is added with this commit.

app/public/cantusdata/__init__.py

@@ -2,8 +2,6 @@
 from django.db.models.signals import post_migrate
 from .celery import app as celery_app
 
-default_app_config = "cantusdata.CantusdataConfig"
-
 
 class CantusdataConfig(AppConfig):
     name = "cantusdata"

app/public/cantusdata/settings.py

@@ -46,7 +46,7 @@
     "django_celery_results",
     "rest_framework",
     "rest_framework.authtoken",
-    "cantusdata",
+    "cantusdata.CantusdataConfig",
     "django_extensions",
     "coverage",
 )

app/public/cantusdata/signals/solr_sync.py

@@ -69,7 +69,7 @@ def folio_or_manuscript_saved(self, sender, instance, created, **kwargs):
         with self.get_session() as sess:
             sess.schedule_update(instance, is_new=created)
 
-    def folio_or_manuscript_deleted(self, sender, instance, **kwargs):
+    def folio_or_manuscript_deleted(self, sender, instance, using, **kwargs):
         with self.get_session() as sess:
             sess.schedule_deletion(instance)
 
@@ -81,7 +81,7 @@ def chant_saved(self, sender, instance, created, **kwargs):
                 sess.schedule_update(instance.folio)
                 sess.schedule_update(instance.manuscript)
 
-    def chant_deleted(self, sender, instance, **kwargs):
+    def chant_deleted(self, sender, instance, using, **kwargs):
         with self.get_session() as sess:
             sess.schedule_deletion(instance)
             sess.schedule_update(instance.folio)