If you find this horrifying (and I hope you do, because there can be no moral justification for celebrating murder), then I encourage you to really think about whether we would not be better off without such extremist language poisoning people's minds. We have to try to stop escalating, or the cycle is going to destroy our society.
As someone of Eastern European origins I would celebrate Vladimir Putin's murder, especially since he's responsible for the murder for so many in Ukraine today (both Russians and Ukrainians). I think the reality is a touch more nuanced than the absolutist ethical stance.
Could you say the same if he murdered your friends, family, children? All for what? That man has no respect for human life, civilization or diplomacy.
While within a civilization we can afford each other grace, it remains important for the very security of our civilization that we retain our malice and use it sparingly on those who seek to destroy it. Otherwise i fear that we only believe in it because its convenient or makes us feel morally superior. Do really believe in it if you're not willing to get your hands bloody to defend it? If you were capable of defending it, would you not celebrate the victory?
Putin being murdered tomorrow would create a significant opportunity for peace in the region and spare many, many lives. Such an event would be worthy of cheer.