As a robotics platform, there's nothing inherently weaponizable about quadrupedal locomotion over, say, a quadcopter. Weaponizing this system would be almost as difficult as developing and then weaponizing the system.
If you're worried about weaponization of open source projects, your threat actors are just about any person with a computer, a couple thousand dollars and a grudge.
Boston Dynamics robot with gun: Quote: "At the Association of the US Army’s annual conference last week, Ghost Robotics unveiled its Vision 60 quadrupedal robot, which wielded a custom-made gun atop its already eerie figure."
https://www.extremetech.com/extreme/328299-robot-dogs-now-fi...
That said, I am not sure that a quadruped robot is much better for delivering a bomb than an RC car, other than a slight edge on rough terrain. Both would have an advantage over flying, since weight is a problem for drones.