Upgrade a Postgres DB in Docker (e.g. for paperless-ngx)

• this guide adheres to the recommendation of the postgres documentation to use the version of pg_dumpall from the postgres version you're upgrading to, not the old/curent one https://www.postgresql.org/docs/current/upgrading.html#UPGRADING-VIA-PGDUMPALL
• shutdown paperless-ngx and postgres
• write a temp.yaml compose file:

services:
  old:
    image: postgres:13
    container_name: pg13
 volumes: