Fix retrying tasks (#5160)

# What this PR does
Small fixes for some retrying tasks

## Which issue(s) this PR closes
https://github.com/grafana/oncall-private/issues/2965
https://github.com/grafana/oncall-private/issues/2964

## Checklist

- [ ] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] Added the relevant release notes label (see labels prefixed w/
`release:`). These labels dictate how your PR will
    show up in the autogenerated release notes.

engine/apps/alerts/models/alert_receive_channel.py

@@ -422,6 +422,8 @@ class AlertReceiveChannel(IntegrationOptionsMixin, MaintainableObject):
 
     @property
     def new_incidents_web_link(self):
+        from apps.alerts.models import AlertGroup
+
         return UIURLBuilder(self.organization).alert_groups(
             f"?integration={self.public_primary_key}&status={AlertGroup.NEW}",
         )

engine/apps/alerts/tasks/notify_user.py

@@ -400,7 +400,7 @@ def perform_notification(log_record_pk, use_default_notification_policy_fallback
         UserNotificationPolicyLogRecord(
             author=user,
             type=UserNotificationPolicyLogRecord.TYPE_PERSONAL_NOTIFICATION_FAILED,
-            notification_policy=notification_policy,
+            notification_policy=notification_policy if not use_default_notification_policy_fallback else None,
             reason="Expected data is missing",
             alert_group=alert_group,
             notification_step=notification_policy.step if notification_policy else None,
@@ -424,7 +424,7 @@ def perform_notification(log_record_pk, use_default_notification_policy_fallback
         UserNotificationPolicyLogRecord(
             author=user,
             type=UserNotificationPolicyLogRecord.TYPE_PERSONAL_NOTIFICATION_FAILED,
-            notification_policy=notification_policy,
+            notification_policy=notification_policy if not use_default_notification_policy_fallback else None,
             reason="Skipped notification because alert group is resolved",
             alert_group=alert_group,
             notification_step=notification_policy.step if notification_policy else None,