fix: alter existing delete_at field to allow NULL values

apps/event_hub/migrations/0007_alter_delete_at_nullable.py

@@ -0,0 +1,21 @@
+from django.db import migrations, models
+from django.db.utils import ProgrammingError
+
+def make_delete_at_nullable(apps, schema_editor):
+    # Get the database connection
+    connection = schema_editor.connection
+
+    with connection.cursor() as cursor:
+        # Alter column to allow NULL
+        cursor.execute(
+            "ALTER TABLE event_hub_eventlog ALTER COLUMN delete_at DROP NOT NULL"
+        )
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('event_hub', '0006_make_delete_at_nullable'),
+    ]
+
+    operations = [
+        migrations.RunPython(make_delete_at_nullable, migrations.RunPython.noop),
+    ]