tweak restricted_at database migration

engine/apps/alerts/migrations/0027_remove_alertreceivechannel_restricted_at.py

@@ -1,19 +0,0 @@
-# Generated by Django 3.2.20 on 2023-07-25 09:47
-
-from django.db import migrations
-import django_migration_linter as linter
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('alerts', '0026_auto_20230719_1010'),
-    ]
-
-    operations = [
-        linter.IgnoreMigration(),
-        migrations.RemoveField(
-            model_name='alertreceivechannel',
-            name='restricted_at',
-        ),
-    ]

engine/apps/alerts/migrations/0027_remove_alertreceivechannel_restricted_at_from_state.py

@@ -0,0 +1,20 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("alerts", "0026_auto_20230719_1010"),
+    ]
+
+    operations = [
+        migrations.SeparateDatabaseAndState(
+            state_operations=[
+                migrations.RemoveField(
+                    model_name="alertreceivechannel",
+                    name="restricted_at",
+                ),
+            ],
+            database_operations=[],
+        )
+    ]

engine/apps/alerts/models/alert_receive_channel.py

@@ -198,6 +198,9 @@ class AlertReceiveChannel(IntegrationOptionsMixin, MaintainableObject):
     rate_limited_in_slack_at = models.DateTimeField(null=True, default=None)
     rate_limit_message_task_id = models.CharField(max_length=100, null=True, default=None)
 
+    # TODO: drop this field in a subsequent release
+    restricted_at = models.DateTimeField(null=True, default=None)
+
     class Meta:
         constraints = [
             models.UniqueConstraint(