Version in base suite: 15.4-7
Version in overlay suite: 15.6-1~deb11u1

Base version: shim_15.6-1~deb11u1
Target version: shim_15.7-1~deb11u1
Base files: shim_15.6-1~deb11u1.dsc
Target files: shim_15.7-1~deb11u1.dsc

-W: newer-standards-version 4.4.1 (current is 4.3.0)