Perhaps it should be a one-way arrow. Cyberpunk is part of speculative fiction; If it isn't speculative fiction, can it be cyberpunk? (I am unfamiliar with the subgenre so would not be able to say for sure.) Similarly, I consider "mystery" one perquisite of hard-boiled noir.

Sayers is certainly hard-boiled noir in tone; but how is Lord Peter a hard-boiled detective?