fix: code rabbit suggestion

Author: grv-saini-20

infrastructure/eid-wallet/src/routes/(app)/scan-qr/+page.svelte

@@ -84,13 +84,10 @@ onMount(() => {
     return () => {
         disposed = true;
         cleanup?.();
+        cancelScan();
     };
 });
 
-onDestroy(async () => {
-    await cancelScan();
-});
-
 $effect(() => {
     console.log(
         "🔍 DEBUG: selectedBlindVoteOption changed to:",