Quick information about a little manual intervention required:
As starship-git (the new zsh/fish prompt) was hit by a bug its time to use the non -git version.
This will require you to press "y" to the starship-git removal prompt while running:
I'm writing from my memory, but the message was something like: There is unsolvable dependency conflict between starship and starship-git. ZSH worked fine itself, but pacman -Syu ended with this message.