aflplusplus: don't run unit tests with cmocka
aflplusplus: don't run unit tests with cmocka

i don't think running the unit tests really adds anything given that we
have proper integration tests working, and it just introduces another
build dependency and possibility for spurious breakage.

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs