Keep Kodi 18.7 updated

Preformatted textI want to keep OSMC release 2020.11-1 running on my pi 3+. But I like to install all security fixes for the system over SSH. When I try to do a sudo apt upgrade it says I should use sudo apt full-upgrade instead. But this will upgrade all packages to the latest release including kodi 19.1 which I don’t want. What it the correct way, to keep the system updated? Will there even be any updates or should I just forget about it?

Unfortunately, what you are trying to do is unsupported and will ultimately result in a broken system.

You could comment out the line:
deb buster main
in /etc/apt/sources.list. But as @ActionA says, sooner or later something will break.

Ok so I better just don’t install any updates. Thanks for your help.