fix(async-stack): clean up old cancel listener in enhance-dialog

Author: vnphanquang

.changeset/khaki-worms-flow.md

@@ -0,0 +1,5 @@
+---
+'@svelte-put/async-stack': patch
+---
+
+(experimental) clean up old `cancel` listener in `enhanceDialog`

packages/async-stack/src/helpers/enhance-dialog.js

@@ -73,6 +73,7 @@ export function enhanceDialog(item, options) {
 				dialog.removeEventListener('click', onclick);
 				dialog.removeEventListener('clickbackdrop', onclickbackdrop);
 				dialog.removeEventListener('close', onclose);
+				dialog.removeEventListener('cancel', oncancel);
 			};
 		},
 	};