While I wouldn’t recommend SmartThings as a primary security system as it is just not reliable enough (see many discussions in the forums), the usual method for addressing this issue is to use hardwired sensors and then cut power to them altogether for the Sabbath. It’s only the battery powered ones that have the issue of operating independently.
If you do want to use these kinds of sensors with SmartThings for home automation or convenience cases, there is a community – created integration method that can work well:
The other alternative is the old “NikeNet” solution of going around the house and removing batteries from individual sensors as part of Sabbath preparation. It works, it’s just inconvenient. 