No, there isn't anything above the normal nozzle restrictor in the fuel filler neck which is easily bypassed if you force it.
As above, I'd suggest just getting a
sticker made making it obvious it's a diesel. Maybe one in the dashboard cluster.
Or if it's a REAL issue and you don't want to risk it after its been done before, cancel your order and buy a petrol. Then it's basically impossible since a diesel pump generally won't fit in a petrol filler neck. Surely lightning can't strike twice?