There is no change in PEAR upstream. It has not been deprecated nor is it included with PHP. Instead, the maintainer of the Arch Linux package decided to no longer package it.[1]
Are you sure your GroupWare app needs PEAR? PEAR is usually only used to install dependencies, which can also be done in some other way. [1] https://pierre-schmitz.com/php-7-on-arch-linux/
