There are currently two different ways to exclude devices from the scope in Vanta. One way is to toggle the devices out of scope manually; see, Frequently Asked Questions: How do I Mark Resources out of Scope?
Another method is to add the devices to a smart or static group named VantaNoAlert. Administrators can follow the instructions from Jamf here on making static and smart groups. Once the devices are added to these groups, they will no longer be in scope in Vanta.