Slave Race: Actually, mostly averted (with the provisos mentioned under Slave Mooks) – since We Will Use Manual Labor in the Future is averted, apart from war (again, see Slave Mooks, and preferably with tactical enslavement) about the only practical use of biological slaves is “pleasure slaves” (for which, obviously, one’s own species is preferable) or slave gladiators, or for oppression-based status games, which are all ways to hang a big old “we’re evil, come smash us” sign over one’s own head. Not that that always works – in practice, it works only somewhat better than our efforts to eradicate slavery here on Earth – but it’s something.
AI slavery is rather more common, but since that gets at least two of the Great Powers (the Empire and the Photonic Network), one lesser power (the Silicate Tree) which is not at all shy about using, ah, asymmetrical warfare, and a passel of NGOs at least some of which are inclined to direct action all pissed off at you, it’s can often be made more trouble than it’s worth to maintain.