Missing item reference causing patron action session to not expire

See CIRC-926 and CIRC-726.

Overview: See sduvvuri's comment on CIRC-726, "We ran into this exact same situation again in couple of environments running mod-circulation-19.2.8 where several check-in/check-out patron sessions were stuck due to a loan having references to deleted items."

Steps to reproduce:

1. Check out item
2. Delete item from inventory
3. End session

OR

1. Check in item
2. Delete item from inventory
3. End session