meson: ci: dontmerge: Add additional CI coverage

This is part of the series to be able to test meson on more platforms than
normally part of CI.

Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Author: Justin Pryzby <pryzby@telsasoft.com>

Author: anarazel