Move notifications to signals

bookwyrm/models/__init__.py

@@ -14,7 +14,6 @@ from .status import Review, ReviewRating
 from .status import Boost
 from .attachment import Image
 from .favorite import Favorite
-from .notification import Notification
 from .readthrough import ReadThrough, ProgressUpdate, ProgressMode
 
 from .user import User, KeyPair, AnnualGoal
@@ -29,6 +28,8 @@ from .site import PasswordReset, InviteRequest
 from .announcement import Announcement
 from .antispam import EmailBlocklist, IPBlocklist
 
+from .notification import Notification
+
 cls_members = inspect.getmembers(sys.modules[__name__], inspect.isclass)
 activity_models = {
     c[1].activity_serializer.__name__: c[1]