No it has not - what you refer to is the information page
The cloneurl is still the same - you can use these urls where albeit more correct the .git is optional
https://aur.archlinux.org/iriunwebcam-bin.git
https://aur.archlinux.org/iriunwebcam-bin
You didn’t read the topic then
At the time this guide was writting - the updpkgsums command was necessary as the PKGBUILD was not well maintained.
The command is there - you just didn’t see it. And in the final parts of the guide you install using pacman -U command (replace $VERSION with the actual version from the filename)
sudo pacman -U iriunwebcam-bin-$VERSION.pkg.tar.zst