For the busy or impatient users here’s a short version first:
update your system normally
after the update, install package eos-hooks
Then some more explanation for not-so-busy users.
Just released a new version 5-2.3 of package endeavouros-theming.
The hooks that caused trouble for many users are now deleted from that package, and they have been moved to another package.
This means that you need to first update your system normally, so that you have the new endeavouros-theming package installed. Then you’ll notice that under folder /etc/pacman.d/hooks files os-release.hook and lsb-release.hook are gone.
Then, if you want to have the hooks (you probably would), install the new package eos-hooks. After that those hook files will re-appear, back where they belong.