New comment by Chocimier on void-packages repository

https://github.com/void-linux/void-packages/issues/38306#issuecomment-1196887239

Comment:
Upgrading major version requires some manual steps described at <https://www.postgresql.org/docs/current/upgrading.html>. That's why versions 12-14 were provided in numbered packages for last two years.
If you choose method that requires presence of old binaries, you can get them from cache (<https://docs.voidlinux.org/xbps/advanced-usage.html#downgrading>)  or build with xbps-src.

There was no clean way to remove long unsupported 9.6, sorry.