feat: Implement disable password authentication for users with social accounts

backend/server/users/backends.py

@@ -0,0 +1,16 @@
+from django.contrib.auth.backends import ModelBackend
+from allauth.socialaccount.models import SocialAccount
+
+class NoPasswordAuthBackend(ModelBackend):
+    def authenticate(self, request, username=None, password=None, **kwargs):
+        print("NoPasswordAuthBackend")
+        # First, attempt normal authentication
+        user = super().authenticate(request, username=username, password=password, **kwargs)
+        if user is None:
+            return None
+        
+        if SocialAccount.objects.filter(user=user).exists() and user.disable_password:
+            # If yes, disable login via password
+            return None
+        
+        return user