(composefs backend): Linux 7.0.1 fails to boot with error "has no fs-verity digest"

When attempting to boot a system off of the composefs backend, it fails to switch root. This does not happen on an equivalent system running 6.19.14. Screenshots from a vm: <img width="2201" height="337" alt="Image" src="https://github.com/user-attachments/assets/41f34df5-9482-4f43-89e2-cccad2219db8" /> Kernel version used (taken from https://koji.fedoraproject.org/koji/buildinfo?buildID=2985771): <img width="796" height="250" alt="Image" src="https://github.com/user-attachments/assets/707892bc-877e-4439-995a-4832c73c15bb" /> These errors are observed on the release version of bootc 1.15.1.