migrations: Allow zulipinternal bots to delete their own messages.

zerver/lib/server_initialization.py

@@ -33,6 +33,7 @@ def create_internal_realm() -> None:
     # is changed later before the transaction is committed.
     for permission_configuration in Realm.REALM_PERMISSION_GROUP_SETTINGS.values():
         setattr(realm, permission_configuration.id_field_name, -1)
+    realm.delete_own_message_policy = 1
     realm.save()
 
     RealmAuditLog.objects.create(

zerver/migrations/0563_zulipinternal_can_delete.py

@@ -0,0 +1,13 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("zerver", "0562_remove_realm_create_web_public_stream_policy"),
+    ]
+
+    operations = [
+        migrations.RunSQL(
+            "UPDATE zerver_realm SET delete_own_message_policy = 1 where string_id = 'zulipinternal'"
+        )
+    ]