Fix telegram retrying task after alert group was deleted (#3546)

# What this PR does

## Which issue(s) this PR fixes
https://github.com/grafana/oncall-private/issues/2379

## Checklist

- [ ] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)

---------

Co-authored-by: Joey Orlando <joey.orlando@grafana.com>

engine/apps/email/tests/test_inbound_email.py

@@ -1,4 +1,5 @@
 import json
+
 import pytest
 from django.urls import reverse
 from rest_framework import status

engine/apps/telegram/tasks.py

@@ -226,8 +226,19 @@ def on_alert_group_action_triggered_async(log_record_id):
     from .alert_group_representative import AlertGroupTelegramRepresentative
 
     logger.info(f"AlertGroupTelegramRepresentative ACTION SIGNAL, log record {log_record_id}")
-
-    log_record = AlertGroupLogRecord.objects.get(pk=log_record_id)
+    # temporary solution to handle cases when alert group and related log records were deleted
+    try:
+        log_record = AlertGroupLogRecord.objects.get(pk=log_record_id)
+    except AlertGroupLogRecord.DoesNotExist as e:
+        retries_count = on_alert_group_action_triggered_async.request.retries
+        if retries_count >= 10:
+            logger.error(
+                f"AlertGroupTelegramRepresentative: was not able to get AlertGroupLogRecord, probably alert group "
+                f"was deleted. log record {log_record_id}, retries: {retries_count}"
+            )
+            return
+        else:
+            raise e
 
     instance = AlertGroupTelegramRepresentative(log_record)
     if instance.is_applicable():