Isn’t IOS XE limited to the ASR 9000 series?
I doubt Maricopa is running those.
No, you're thinking of IOS-XR. IOS-XE runs on just about everything now, from routers and switches, down to the access points. The switches (minus the 9200s) and routers can run LXC containers. And that's just the Cisco world.
Even some platforms running DD-WRT can run docker containers now. With MCUs in everything now (ok, maybe not toothbrushes -- yet), anything that touches the network is a potential "computer". I have a $5 ESP32 MCU sitting here on my desk running my own micropython code that can connect via bluetooth or wifi. It's a little bigger than my thumbnail and can run off a LiPo battery at 3.3v. Security-minded folks MUST keep these vectors in mind.