New issue by Dishayloo on void-packages repository

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

Description:
I regularly update my system with xbps-install -Suv. I noticed postgres wasn't working anymore and realized that I now have postgresql14 installed and the old postgres-Installation is gone. So I configured the new postgres to run with runit (which works) and wanted to convert my old data-dir. This is not working, apparently as the old postgres-Binaries are missing.

Here is my console attempt:

```
$ sudo su postgres
$ pg_upgrade -c -d /var/lib/postgresql/data -b /usr/lib/postgresql/ -D /var/lib/postgresql14/data

Prüfen von »/usr/lib/postgresql/postgres« fehlgeschlagen: keine reguläre Datei
Fehlgeschlagen, Programm wird beendet
```

The output is in german, but it basically means: check for »/usr/lib/postgresql/postgres« failed: no regular file; Failed, program is terminated
This is as the old postgres-binaries are not present anymore - or I don't know where they are.