Levelling up Boost.Redis

https://cppalliance.org/ruben/2025/10/07/Ruben2025Q3Update.html

Per‑operation cancellation via asio::cancel_after is added in Boost.Redis 1.90, together with custom startup commands replacing HELLO, Valkey support, race‑free cancellation handling, and upcoming Sentinel and health‑check enhancements.