Mouse behaviour: left click produces "c", middle click produces "v"

UTM Version 4.7.5 (118) running on Macbook M5 Pro, OS 26.5.1 (25F80)

Trying to setup some Linux VMs and experiencing strange mouse behaviour: left mouse button produces an additional "c" keystroke, middle mouse button an additional "v".

- Problem occurs with external mice and also using the laptop's touchpad.
- Problem seems not to be related to Linux since it even occurs in the GRUB CLI, before any kernel has been booted.
- From within Linux, tools such as "xinput" confirm that the mouse clicks trigger exactly the same key codes as the keyboard would.
- Problem occurs with QEMU and with Apple Virtualization.

XFCE desktop reports 3 simulatanous input devices: "QEMU QEMU USB tablet", "QEMU QEMU USB mouse" and "spice vdagent tablet".

This _might_ be related to https://github.com/utmapp/UTM/issues/7375