Looks like knetattach, a KDE plasma package, has files inside plasma-desktop so you get an error when trying to install knetattach.
error: failed to commit transaction (conflicting files)
knetattach: /usr/bin/knetattach exists in filesystem (owned by plasma-desktop)
knetattach: /usr/share/applications/org.kde.knetattach.desktop exists in filesystem (owned by plasma-desktop)
Looks like knetattach, a KDE plasma package, has files inside plasma-desktop so you get an error when trying to install knetattach.