TASK: Don’t set return type for RedisBackend->key()
TASK: Don’t set return type for RedisBackend->key()

This change removes the return type for the key function within the RedisBackend. This is necessary as the method can return a bool as well as a string.

Fixes #1311

neos/flow-development-collection,dlubitz/flow-development-collection,bwaidelich/flow-development-collection,kdambekalns/flow-development-collection,fcool/flow-development-collection,bwaidelich/flow-development-collection,neos/flow-development-collection,fcool/flow-development-collection,neos/flow-development-collection,kdambekalns/flow-development-collection,neos/flow-development-collection,aertmann/flow-development-collection,daniellienert/flow-development-collection,aertmann/flow-development-collection,fcool/flow-development-collection,robertlemke/flow-development-collection,albe/flow-development-collection,daniellienert/flow-development-collection,kdambekalns/flow-development-collection,daniellienert/flow-development-collection,albe/flow-development-collection,albe/flow-development-collection,robertlemke/flow-development-collection,fcool/flow-development-collection,bwaidelich/flow-development-collection,dlubitz/flow-development-collection,robertlemke/flow-development-collection,kdambekalns/flow-development-collection,dlubitz/flow-development-collection,robertlemke/flow-development-collection,aertmann/flow-development-collection