Update OpenZaak to v1.13 in development docker-compose

[MLenterman]

New Postgres version is required(can use postgres/postgis instead of current one). Initial attempt threw an error that had something to do with Notificaties API. In our development docker-compose we disabled Notificaties API with an environment variable. Not sure if that is no longer possible or if something else is going on. I already have a prototype docker-compose.notificaties-api.dev.yml laying around if it turns out we need to add it to the stack. Something also seems to have also changed surrounding "fixtures", which we use to auto-configure credentials in OpenZaak.