redis 7.x-3.11

This is maintenance release, as usual all users should upgrade.

This new release brings a single performance improvement that follows the path of the 7.x-3.10 release: when the cache backend reads the latest flush timestamp it caches statically in a smart way instead of reading it from Redis on each cache item fetch, it reduces by half the number of Redis commands being sent to the server during normal operations.

People with no performance problems are not urged to upgrade, people with potential contention or network speed problems might benefit from this release.