The lockscreen is already initiated through kscreenlockerrc, no need to do it twice
startplasma-waylandsession hasn't existed for a while and the whole session launched just fine without it, so let's remove the entire argument. The binary was removed in plasma-workspace in 7884f53d3c07699dc16f07cf0aa3966802c503c8
Now that we have the convergentwindows script, the window decorations are managed by them.