Whenever I shut down a Lenovo Thinkpad 20H2-S00700, a very loud and annoying
beep is played. This has been reported on various pages like 
https://www.reddit.com/r/openSUSE/comments/x58yiv/after_tw_update_my_systems_rudely_beep_at_me/
or
https://forum.endeavouros.com/t/solved-loud-beep-at-shutdown/27389/34

however, blacklisting pcspkr didn't help on my system ��������� now the beep is coming
through the stereo speakers. I can only prevent the beeping by muting sound
altogether via pulseaudio.

This might be the same bug as on Fedora:
https://bugzilla.redhat.com/show_bug.cgi?id=2129387
However, as for me, it is not connected to suspend and resume, but it happens
at normal poweroff.
The workaround in comment #4 DOES silence the beeping for the current session,
but does not persist for the next session:

  busctl set-property org.freedesktop.login1 /org/freedesktop/login1
org.freedesktop.login1.Manager EnableWallMessages b false