Valkey speaks the Redis protocol, so the redis adapter (go-redis) already
serves it. Dropping valkey-go removes a dependency and shrinks the stripped
binary by about 9 MB.
The redis adapter now also closes a client that failed to connect only once.
BREAKING CHANGE: `adapter: valkey` is no longer accepted. Use
`adapter: redis` with a redis:// or rediss:// URL instead of valkey:// or
valkeys://. The namespace option now applies to these services.
tiennm99