Update TCI-thorn-cross.yml
Update TCI-thorn-cross.yml

Removed the 26th and 31st December from unbookable. This is because there are no Thursday visits in Thorn Cross prison.
ministryofjustice/prison-visits-2,ministryofjustice/prison-visits-2,ministryofjustice/prison-visits-2,ministryofjustice/prison-visits-2