Update vapi/gtk4.vapi
failed to build UI from file: on_drop
signal not exist
<object class="GtkDropTarget">
<property name="actions">copy</property>
<property name="formats">GdkFileList text/uri-list</property>
<signal name="on_drop" handler="on_drag_data_received" />
</object>
Edited by TAO ZUHONG