Comment by purerandomness

Arch has a package [0] called postgresql-old-upgrade that tracks the second-last postgres version specifically for upgrading. It's described in their Wiki [1]

If you need older versions, they're available via AUR, called postgres-*-upgrade [2]

[0] https://archlinux.org/packages/?name=postgresql-old-upgrade

[1] https://wiki.archlinux.org/title/PostgreSQL#pg_upgrade

[2] https://aur.archlinux.org/packages/postgresql-12-upgrade