If you restrict how users run your software, then it is not free software, by the definition of both the FSF and OSI. An anti-weaponization clause is no different from an anti-commercialism clause in this context.
There are many licenses with mortality clauses but they are general not popular because the ambiguity and "supply chain risk" of having such a license in a dependency tree tends to limit adoption of any projects that use them.
What’s to prevent the Bad Guys from illegally using your code, while the Good Guys cannot and have to settle on an inferior solution to fight the Bad Guys?
Or (now gonna get creative here, to invent counterexamples of why this is not a good idea) one that cannot be used in software that is used to teach children about evolution!
I imagine that many missiles, drones and other such devices use free software. I wouldn't want any of my software to be part of these weapons.