fix compatibility with TwigBridge < 7.3

Author: xabbuh

src/Symfony/Component/Mailer/EventListener/MessageListener.php

@@ -122,7 +122,7 @@ private function setHeaders(Message $message): void
 
     private function translateSubject(Message $message): void
     {
-        if (!$message instanceof TemplatedEmail || !$this->translator || !$message->getTranslatableSubject() instanceof TranslatableMessage) {
+        if (!$message instanceof TemplatedEmail || !$this->translator || !method_exists(TemplatedEmail::class, 'getTranslatableSubject') || !$message->getTranslatableSubject() instanceof TranslatableMessage) {
             return;
         }
 

src/Symfony/Component/Mailer/Tests/EventListener/MessageListenerTest.php

@@ -120,6 +120,10 @@ public static function provideHeaders(): iterable
 
     public function testTranslatableSubject()
     {
+        if (!method_exists(TemplatedEmail::class, 'getTranslatableSubject')) {
+            $this->markTestSkipped('symfony/twig-bridge 7.3 or higher required');
+        }
+
         $message = new TemplatedEmail();
         $message->subject(new TranslatableMessage('hello.world'));
         $listener = new MessageListener(translator: new class implements TranslatorInterface {

src/Symfony/Component/Mailer/composer.json

@@ -21,7 +21,7 @@
         "psr/event-dispatcher": "^1",
         "psr/log": "^1|^2|^3",
         "symfony/event-dispatcher": "^6.4|^7.0",
-        "symfony/mime": "^7.3",
+        "symfony/mime": "^7.2",
         "symfony/service-contracts": "^2.5|^3"
     },
     "require-dev": {