klipper: Finish processing all new mimedata tasks before setting clipboard
In wayland in the current form setClipboard will perform a roundtrip In that roundtrip we can get and process new mimedata, leaving our current mimeData object dangling.
Moving this set to the end should hide the issue.
SENTRY: PLASMA-WORKSPACE-1BCJ
Longer term Qt6.9 provides a much cleaner way of doing wlr_data_control integration which gets rid of all hacks or issues with dependency ordering.