How can I change my app's Package.appxmanifest file to deny requiring RunFullTrust mode?

Question

I don't know why the MS Store is claiming that my app is demanding RunFullTrust mode. When I try to prepare my app for submission to the Microsoft Store, it tells me:

I don't believe my app needs to run full trust, but I see nothing in Package.appxmanifest that indicates it should be, so I don't know what it is that I need to change.