IP networks are packet-switched networks, where a circuit has multiple "conversations" (packets of different flows) running over it.
Circuit-switched networks have a single conversation over a circuit, which is dedicated to the single conversation during the conversation. For example, the traditional PSTN (Public Switched Telephone Network).
Your example has permanent circuits, not switched circuits. The links between the routers do not change, and those links can carry packets from many different flows, so the network is a packet-switched network.