New comment by sgn on void-packages repository

https://github.com/void-linux/void-packages/pull/29544#issuecomment-809397657

Comment:
Anyway, I'm not sure if below approach works:
- Package `zlib-ng` as separated package, `conflicts=zlib>=0; replace=zlib>=0; provides=zlib-0.1`
- Whoever want `zlib-ng`, install `zlib-ng` themselves.