Docker: migrate from bind mounts to named volumes

docker/postgres/docker-compose.toml

@@ -1,3 +1,6 @@
+[volumes]
+data = {}
+
 [services.postgres]
 container_name = "postgres"
 image = "postgres:16"
@@ -5,7 +8,7 @@ environment = ["TZ=Europe/Helsinki"]
 ports = ["127.0.0.1:5432:5432"]
 networks = ["postgres"]
 volumes = [
-  "/docker/postgres:/var/lib/postgresql/data",
+  "data:/var/lib/postgresql/data",
   "/etc/localtime:/etc/localtime:ro",
 ]
 restart = "unless-stopped"