Moon of Alabama mentions it here, says it was the week before the invasion that Zelensky was opening his mouth about nukes

https://www.moonofalabama.org/2022/02/disarming-ukraine-day-1.html

Like me and many other analysts Mearsheimer did not expect that a Russian move into the Ukraine would happen. Why the Russian government finally decided to take that step is not clear to me. I believe that Zelensky’s lose talk about acquiring nuclear weapons for the Ukraine was one of the decisive factors. Who told Zelensky to come up with that?

another MoA post has the actual source, can’t find it, but you got them in the other reply