chore(deps): upgrade ioredis from 4 to 5
Because: - FxA used ioredis 4 with community types; ioredis 5 ships its own types. This commit: - Bumps ioredis to ^5.11.1 in root, auth-server and fxa-shared; drops @types/ioredis. - Replaces the Redis.Redis and Redis.RedisOptions namespace types. - Lets the metering DedupePipeline.exec type return null and throws DedupeError on null. - Quits the Redis client in two lib integration specs so Jest exits. Closes FXA-5410