fix navigating when files are dropped

packages/html/src/events/drag.rs

@@ -110,6 +110,8 @@ impl PointerInteraction for DragData {
 #[derive(serde::Serialize, serde::Deserialize, Debug, PartialEq, Clone)]
 pub struct SerializedDragData {
     mouse: crate::point_interaction::SerializedPointInteraction,
+
+    #[serde(default)]
     files: Option<crate::file_data::SerializedFileEngine>,
 }