I recall videos of quadcopters dropping grenades and mortar rounds (for accuracy - they can drop one within a trench or at the door of a trench-shelter, unlike firing a mortar from distance) as improvised weapons a few years ago in the Ukraine Donbass conflict.

More advanced "loitering munitions" (essentially, drones that fly around until they're sent to slam into a target) were used in the recent Nagorno-Karabakh conflict.

I believe that all these cases were human-in-the-loop for various reasons, but the possibility for automated targeting seems reachable soon if the armies would really want it (which is not certain).