Add comment field to subevents (Z#23148472) (#4099)

* Add comment field to subevents (Z#23148472)

* Review fix

src/pretix/base/migrations/0262_subevent_comment.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.2.10 on 2024-04-19 14:44
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("pretixbase", "0261_userknownloginsource"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="subevent",
+            name="comment",
+            field=models.TextField(null=True),
+        ),
+    ]