Trying to resinstall gives me:
$ yay -S archlinux-keyring
warning: archlinux-keyring-20221123-1 is up to date -- reinstalling
resolving dependencies...
looking for conflicting packages...
Package (1) Old Version New Version Net Change
core/archlinux-keyring 20221123-1 20221123-1 0,00 MiB
Total Installed Size: 1,58 MiB
Net Upgrade Size: 0,00 MiB
:: Proceed with installation? [Y/n]
(1/1) checking keys in keyring [----------------------------------------------------------------------------------------] 100%
(1/1) checking package integrity [----------------------------------------------------------------------------------------] 100%
error: archlinux-keyring: signature from "Christian Hesse (Arch Linux Package Signing) <arch@eworm.de>" is unknown trust
:: File /var/cache/pacman/pkg/archlinux-keyring-20221123-1-any.pkg.tar.zst is corrupted (invalid or corrupted package (PGP signature)).
Do you want to delete it? [Y/n] Y
error: failed to commit transaction (invalid or corrupted package (PGP signature))
Errors occurred, no packages were upgraded.
-> error installing repo packages
Solved it via https://forum.archlinux.de/d/34531-update-mit-fehlermeldung:
sudo rm -r /etc/pacman.d/gnupg
sudo pacman-key --init
sudo pacman-key --populate archlinux
sudo pacman-key --refresh-keys
sudo pacman -Sy gnupg archlinux-keyring