QQuickWindow sometimes commits a buffer with the old size after a configure is acked.

This greatly confuses compositors.

We will commit an old sized buffer, but still call set_window_geometry with the new size, making compositors think the rest of the buffer is shadows. It also seems to confuse sway a lot.

Log and minimal example attached.

To reproduce, maximize and then unmaximize the window, when unmaximizing a frame with the old size is sometimes committed.