New review comment by ahesford on void-packages repository

https://github.com/void-linux/void-packages/pull/39488#discussion_r981488614

Comment:
In light of that, the common stuff should definitely be moved into a common subpackage that each `lib*` package can depend on. The `webkit2gtk` package itself should could either contain whatever the "default" version is (if a sensible default can be defined).