Title. Tried to search, found instructions on how to do it in debian-adjacent distros, but I’m in openSUSE, which doesn’t use dpkg.
I also checked the manpage for zypper and found nothing that seemed the part, though I don’t exclude the possibility that I just failed to read it properly.
No worries, I wouldn’t know this, if I had not been in exactly the same situation, desperately trying to free up space by deleting packages and it just not working. Also, Snapper is easy to forget about, which is really a testament to how good it generally is.