The package description states:
“Sudo reads either /etc/sudoers or /usr/etc/sudoers
(in that order, whichever one it finds first), to determine what users have
access to sudo and which commands they can run.”
So copy the file to /etc/sudoers.d/, adapt it and you are ready to go as it can’t get overwritten with a package update.
Simply uninstall and lock package sudo-policy-wheel-auth-self:
sudo zypper rm sudo-policy-wheel-auth-self
sudo zypper al sudo-policy-wheel-auth-self
And since this came as a surprise to you, you might also be surprised about the other changes that were also explained in the Leap 16.0 release notes, so do yourself the favor and read them:
This time it’s not just a “let’s just install and see where that gets us” release. There were real changes that you should be aware of.
I already did not see anything that related to me. I did not understand:
configurations that used the primary or secondary users group as a condition need to have the users group manually added to these user accounts in order to continue to work, for example, to for @users in the sudoers file