Prune widgets on graph configure (#3716)

src/scripts/domWidget.ts

@@ -314,3 +314,18 @@ LGraphNode.prototype.addDOMWidget = function <
 
   return widget
 }
+
+/**
+ * Prunes widgets that are no longer in the graph.
+ * @param nodes The nodes to prune widgets for.
+ */
+export const pruneWidgets = (nodes: LGraphNode[]) => {
+  const nodeSet = new Set(nodes)
+  const domWidgetStore = useDomWidgetStore()
+  for (const widgetState of domWidgetStore.widgetStates.values()) {
+    const widget = widgetState.widget
+    if (!nodeSet.has(widget.node as LGraphNode)) {
+      domWidgetStore.unregisterWidget(widget.id)
+    }
+  }
+}