do not assume toString() method (#57340)

Author: cosmastech

src/Illuminate/Notifications/NotificationSender.php

@@ -111,7 +111,7 @@ public function sendNow($notifiables, $notification, ?array $channels = null)
             }
 
             $this->withLocale($this->preferredLocale($notifiable, $notification), function () use ($viaChannels, $notifiable, $original) {
-                $notificationId = Str::uuid()->toString();
+                $notificationId = (string) Str::uuid();
 
                 foreach ((array) $viaChannels as $channel) {
                     if (! ($notifiable instanceof AnonymousNotifiable && $channel === 'database')) {
@@ -216,7 +216,7 @@ protected function queueNotification($notifiables, $notification)
         $original = clone $notification;
 
         foreach ($notifiables as $notifiable) {
-            $notificationId = Str::uuid()->toString();
+            $notificationId = (string) Str::uuid();
 
             foreach ((array) $original->via($notifiable) as $channel) {
                 $notification = clone $original;

src/Illuminate/Support/Testing/Fakes/NotificationFake.php

@@ -314,7 +314,7 @@ public function sendNow($notifiables, $notification, ?array $channels = null)
 
         foreach ($notifiables as $notifiable) {
             if (! $notification->id) {
-                $notification->id = Str::uuid()->toString();
+                $notification->id = (string) Str::uuid();
             }
 
             $notifiableChannels = $channels ?: $notification->via($notifiable);