What about classic flak cannons operated by AI, or things like Phalanx CIWS ( https://en.m.wikipedia.org/wiki/Phalanx_CIWS ) or various automated systems that fire proximity fused ammo?
There are some German AA guns that have been used for counter UAS, but their export laws are a fucking nightmare to deal with if you ever want to sell, give or trade those systems later on.