New comment by xtraeme on void-packages repository

https://github.com/void-linux/void-packages/issues/21044#issuecomment-618527324

Comment:
Yes, they are ignored twice and this is the problem. With lots of subpkgs this will slow it down substantially because it needs to process and ignore the same dependency N times.

Also this change makes "./xbps-src show-build-deps" contains lots of dups as well, and this makes xbps-fbulk(1) fail in some cases.