Change volume mount point from /var/lib/postgresql/data to /var/lib/postgresql

[rmbruntz]

In postgresql 18, the volume has been changed from /var/lib/postgresql/data to /var/lib/postgresql. See here for the relevant commit.

Version 18 was released September 25, so the :latest tag in peppermint's docker-compose.yml now pulls this. Without this change an anonymous volume is created at /var/lib/postgresql every time the container starts. This fixes the mount point for all three docker compose files to be consistent with version 18.

[vercel[bot]]

@rmbruntz is attempting to deploy a commit to the peppermint labs Team on Vercel.

A member of the Team first needs to authorize it.

[raweber42]

Please get this merged :+1: Can confirm that it fixes the problem.