You can. You just need to set their species rights to undesirable.
All I can see is Servitude. Robots have different citizenship standards than normal populations.
EDIT: Nvm, someone already brought it up.
As an addendum, even if that did work it still wouldn't be good enough. What if I have robots filling job spaces because I dont have enough people to fill up a planets job cap yet, but then I get more pops, or I find a species that can do mining or whatever better than my robots are now. Sure you can move the Robots to another planet provided you have space for them to take up there, but there isn't a way to just phase out robotic workers once the planet's population goes up, or I find a species that can do it better. I might not want to outlaw or get rid of all my robots, just a few.
To summarize: the best "solutions" are only partial and convoluted, and a simple "Deconstruct Robot" button like we had pre 2.2 would fix everything.