🔥(backend) remove users systematic return of profile_contact

Custom UserManaged returned profile_contact field when returning users.
While this may be useful later, we'd currently rather have it return users.

src/backend/core/api/viewsets.py

@@ -186,7 +186,7 @@ class UserViewSet(
     """
 
     permission_classes = [permissions.IsSelf]
-    queryset = models.User.objects.all().select_related("profile_contact")
+    queryset = models.User.objects.all()
     serializer_class = serializers.UserSerializer
     throttle_classes = [BurstRateThrottle, SustainedRateThrottle]
     pagination_class = Pagination