Behaviour of Replication::aggregate

Describe the bug Was a TODO in source code.

At least for now we will replicate the previous behaviour of skipping automatic aggregation when using the redis-sentinel backend because $nodes contains an array of sentinel servers instead of Redis servers and SentinelReplication already gets the list of sentinels in the first argument of its constructor. SentinelReplication::add() actually knows how to handle connections marked with role=sentinel in their parameters but relying on it would require an explicit role to be set by the user and I would like to avoid enforcing that for now.

https://github.com/predis/predis/blob/c201af5ad308dd419ddc2494bb7fecaf8a8cd570/src/Configuration/Option/Replication.php#L109-L122