change notifications div scroll behavior and max-height and add a call to update function on deleting a notification

src/components/Header/Header.jsx

@@ -90,6 +90,7 @@ function Header() {
             const result = await deleteNotificationUser(notificationId);
             if (result) {
                 setNotifications(prev => prev.filter(n => n.id !== notificationId));
+                update();
             }
         } catch (err) {
             console.error('Erreur suppression notification :', err);