Thanks for all the comments!
Didn’t know GNOME OS uses plain ostree.
I have successfully updated the image with eos-updater-ctl update !
I got the impression there was nothing to update because no updated packages were shown (as with rpm-ostree) but the update seemed to work fine.
Now I only have to wait for the new GNOME 40 design to be merged with GNOME OS Nightly :-).
I got the impression there was nothing to update because no updated packages were shown (as with rpm-ostree) but the update seemed to work fine.
It’s because there’s no such “packages” in the GNOME OS, it’s just a single base image. You can’t install packages on top of the base image like you’d do with rpm-ostree for example.