I would hope they get rehabilitated into tolerant society rather than murdered.
Murder isn't good. It's necessary at times, but we shouldn't celebrate murder of people in peacetime.

Summary executions come by as a result of the conditions of the society the executed exists in. There is not always time for a fair trial, or the society cannot be trusted to carry out a fair trial or the victims of the criminal are present and carry out the sentence as a result of need for immediate retribution- retribution which we can retroactively acknowledge as just as well. The Barbara pit was a combination of these three, which is why we can retroactively feel as though it was just. Had the partisans rounded up a group of suspected SS members in 1972 and thrown them into a pit, then that would've been a different story. We should want and expect fair trials - even of those that are suspected of heinous deeds. We cannot expect such trials in the modern west currently, but that does not mean we should celebrate summary executions - They are a necessary mean to an end, they are not an end goal to themselves.

Summary executions aren't good in themselves though, and it is not something we should wish for society, or celebrate for a society in general.

Current day? Yeah transphobes get the wall, we can't trust the government to do anything. If some transphobe rocks up to an event wielding a rifle, scaring people and generally escalating the situation, then I hope that person gets got, and Ill laugh about it too.
If we're in some commie utopia were all that's left is to deal with people's regressive views, then I don't think it would be good to make the woke-stazi kick in peoples doors and shoot them on the spot for writing shitty stuff online.

You can have a leftist community, or you can treat bigots with kid gloves. You can't do both.

Where am I advocating for use of kid gloves? Any fair and just society must treat all as equal when it comes to criminal behavior, not having separate classes where some are "more equal". Bigots trying to cause harm should see justice, as much as anyone else.

Summary execution is not something to be lauded or celebrated. Doing so diminishes you as well as much as it does your enemies.