fix: update docker-compose volume mount for PostgreSQL 18+ compatibility (#28282)

PostgreSQL 18+ stores data in /var/lib/postgresql/18/main instead of
/var/lib/postgresql/data. The volume mount needs to be at /var/lib/postgresql
to capture the new directory structure.

Fixes #28281

packages/prisma/docker-compose.yml

@@ -7,7 +7,7 @@ services:
       - "5450:5432" # expose pg on port 5450 to not collide with pg from elsewhere
     restart: always
     volumes:
-      - db_data:/var/lib/postgresql/data
+      - db_data:/var/lib/postgresql
     environment:
       POSTGRES_DB: "cal-saml"
       POSTGRES_PASSWORD: ""