led-matrix does not work under Ubuntu -- switch from pynput to maybe keyboard module

[sjjh]

I wanted to try out your led-matrix using Ubuntu 24.04LTS and get following error message:

Traceback (most recent call last):
  File "/home/user/src/led-matrix/./led_system_monitor.py", line 19, in <module>
    from pynput.keyboard import Key, Listener
ModuleNotFoundError: No module named 'pynput'

A web search revealed, pynput apparently not working under Wayland. A switch to keyboard module is recommended, cf. https://stackoverflow.com/questions/71828671/how-do-i-use-pynput-in-linux-or-is-pynput-not-working-on-linux/75496187#75496187 (even though keyboard seems to be unmaintained -- maybe there is even a better alternative?)