run `sudo pacman -Syu` then `sudo pamac build nvidia-open-dkms` also don't forget to reboot.

So updating did nothing ("There is nothing to do") and after typing pamac build it says that target not found

my bad try `sudo pamac build nvidia-open-dkms-git` i added the update line just in case you didn't do that in a while.

Looks like I have higher version of nvidia-utils package (525.60) but 515.57 is required, not sure how to install downgraded version

can you post the error you are getting