Update North Sea Camp Christmas visit slots
Update North Sea Camp Christmas visit slots

Unbookable:
- Christmas Eve
- Christmas Day
- Boxing Day
- New Year's Eve
- New Year's Day

Slot anomalies:
- 28th Dec 0900-1130 and 1330-1545
ministryofjustice/prison-visits,ministryofjustice/prison-visits,ministryofjustice/prison-visits