Remove cmakelang dependency

The problem

cmakelang has a GPL license. At a minimum, we shouldn't include it in the list of install dependencies.

We need to investigate why this wasn't picked up by the CI because the CI of magicc/copier-fgen-based-repository detected the change.

Definition of "done"

• remove install dependency

Additional context

This is what is blocking copier-fgen-based-repository!5 (merged)