Michael composed on 2021-08-07 14:40 (UTC-0500):
Okay, time for Slávek, or someone else with deeper knowledge to chime in. It might be as simple as just deleting the files, but IDK :(
If dpkg doesn't find them in its database, and they're not part of the currently installed distro, the only things removing them manually can do are free up disk space and remove them from directory listings.