QClipboard does not finalize pasting on wayland

Clipboard clients (e.g., the wl-paste CLI tool) seem to not be notified after receiving clipboard data from QClipboard when running on wayland, presumably due to QClipboard's zwlr_data_control_source_v1 implementation not closing its file descriptor (though that is simply an educated guess).

The attached C++ file is a minimal example, when wl-paste is run together with the example, it never exits (indicating an incomplete transaction). In contrast, pasting data from other programs (e.g., Firefox) results in wl-paste exiting right afterwards (indicating a complete transaction).

The output of both test cases is shown in the attached screenshot.