New review comment by ericonr on void-packages repository

https://github.com/void-linux/void-packages/pull/31615#discussion_r656676195

Comment:
This feels a bit too magical, but idk what others think. Arguably it's because adding `cmake` to hostmakedepends happens automagically already and we end up needing to work around it.

At least having a variable to skip it would be less magical, though also complex.