deontological ethics are explicitly not about that.
I guess it depends on the philosopher, but at least one includes “doing no harm” in the obligations[1]:
Ross [20] modified Kant’s deontology, allowing a plurality of duty-based ethical principles, such as doing no harm, promise keeping, etc.
can you name an ethical system that does concern itself with that?
Probably all consequentialism and at least utilitarianism (harm decreases the global well being). Negative consequentialism is more specifically focused on reducing suffering/harm.