Fix for pipewire being silent on login

Pipewire runs as a user process, and for some reason on my setup it wasn’t working on login.. Symptoms are needing to switch devices to make audio start working.

This fixes it with restart on every login:

In /etc/xdg/autostart/pipewire.desktop put:

[Desktop Entry]
Exec=/usr/bin/systemctl --user restart pipewire
Name=Restart pipewire
Type=Application
X-KDE-StartupNotify=false
OnlyShowIn=KDE;
Icon=plasma
NoDisplay=true

I presume something like that is supposed to be there already, but currently on Debian Testing it isn’t.