Document advanced REDIS connection options

### Describe the Bug

Hi,
I have a containerised Directus application that deploys to Fly.io. Fly.io has a connection to the Upstash Redis service.

My local instance configuration (working)
```
REDIS="redis://user:password@127.0.0.1:16379"
```

My configuration on Fly.io (not working)
```
redis://user:password@fly-example.upstash.io:6379
```

While debugging, I found that for Redis to work you need to set the "family: 6" flag so that the connection is over IPv6. Redis only works on IPv6.
https://community.fly.io/t/connect-to-redis-app-via-internal-network-failing/2776/15

However, I do not know how to set this in Directus.
There seems to be no such flag in the ENV.
https://docs.directus.io/self-hosted/config-options.html#redis

### To Reproduce

Only Deploy on Fly.io.

### Directus Version

10.9.3

### Hosting Strategy

Self-Hosted (Custom)