linux-cachyos 7.0.5-2 package (and friends) in the cachyos-znver4 repo have x86_64_v3 Architecture metadata instead of x86_64_v4.
> sudo pacman -Syyu
...
error: failed to prepare transaction (package architecture is not valid)
:: package linux-cachyos-7.0.5-2-x86_64_v3 does not have a valid architecture
:: package linux-cachyos-headers-7.0.5-2-x86_64_v3 does not have a valid architecture
:: package linux-cachyos-nvidia-open-7.0.5-2-x86_64_v3 does not have a valid architecture
see repo search: