fix(sw, notification): Don't issue an event if there is no affect (#8979)

* test

* ]v]

packages/backend/src/server/api/common/read-notification.ts

@@ -12,13 +12,15 @@ export async function readNotification(
 	if (notificationIds.length === 0) return;
 
 	// Update documents
-	await Notifications.update({
+	const result = await Notifications.update({
 		id: In(notificationIds),
 		isRead: false,
 	}, {
 		isRead: true,
 	});
 
+	if (result.affected === 0) return;
+
 	if (!await Users.getHasUnreadNotification(userId)) return postReadAllNotifications(userId);
 	else return postReadNotifications(userId, notificationIds);
 }