You have two important messages
First pacman fails - second the mhwd script fails because pacman failed.
And you have an unsupported 3rd party repo
Edit your pacman.conf and comment the three/four lines defining the 3rd party repo - save file - start with fixing why pacman fails.
sudo pacman-mirrors --continent
sudo pacman -Syu
This will fix the missing package
$ mbn info linux610-nvidia-470xx -q
Branch : unstable
Name : linux610-nvidia-470xx
Version : 470.256.02-0.2
Repository : extra
Build Date : Sun 21 Jul 2024 06:17:36
Packager : Philip Mueller <philm@manjaro.org>
Branch : testing
Name : linux610-nvidia-470xx
Version : 470.256.02-0.1
Repository : extra
Build Date : Sun 21 Jul 2024 06:04:03
Packager : Philip Mueller <philm@manjaro.org>
Branch : stable
Name : linux610-nvidia-470xx
Version : 470.256.02-0.1
Repository : extra
Build Date : Sun 21 Jul 2024 06:04:03
Packager : Philip Mueller <philm@manjaro.org>