This entry can be deleted alternatively - as the specified kernel does not exist any longer…
→ uninstalled linux-6.0
Building image from preset: /etc/mkinitcpio.d/linux60.preset
fails, because “uninstalled linux-6.0” before…
/etc/mkinitcpio.d/linux60.preset now is just an unwanted leftover
Once you manually modify the preset (is it your case?), I think the preset is kept somehow when the kernel is removed, I have this “issue” from time to time because I forget to manually check and remove what is left behind, when I remove a kernel for which I have modified its preset before.