The lime ppa of krita for ubuntu based distros has been dropped

The lime ppa which was used by ubuntu based distro users has been dropped because it was unmaintained for a long time. Thos who use the ppa may not get krita updates. So it is better to switch to appimages provided by the official website. Or switch to flatpak.

EDIT: it might be coming back in future when a volunteer will pick it up. it will still be unofficial.