[BUGFIX] Prevent TypeError in file related webhook messages

Since FileInterface->getPublicUrl() might return
`NULL`, corresponding constructor arguments are
updated to now expect `?string`.

Resolves: #103051
Releases: main, 12.4
Change-Id: I8d16c6b9361694733dc2c5c4b2e69693fe25cff4
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83011
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Oliver Bartsch <bo@cedev.de>

typo3/sysext/webhooks/Classes/Message/FileAddedMessage.php

@@ -35,7 +35,7 @@ final class FileAddedMessage implements WebhookMessageInterface
     public function __construct(
         private readonly int $storageUid,
         private readonly string $identifier,
-        private readonly string $publicUrl
+        private readonly ?string $publicUrl
     ) {}
 
     public static function createFromEvent(AfterFileAddedEvent $event): self

typo3/sysext/webhooks/Classes/Message/FileRemovedMessage.php

@@ -35,7 +35,7 @@ final class FileRemovedMessage implements WebhookMessageInterface
     public function __construct(
         private readonly int $storageUid,
         private readonly string $identifier,
-        private readonly string $publicUrl
+        private readonly ?string $publicUrl
     ) {}
 
     public static function createFromEvent(BeforeFileDeletedEvent $event): self

typo3/sysext/webhooks/Classes/Message/FileUpdatedMessage.php

@@ -33,7 +33,7 @@ final class FileUpdatedMessage implements WebhookMessageInterface
     public function __construct(
         private readonly int $storageUid,
         private readonly string $identifier,
-        private readonly string $publicUrl,
+        private readonly ?string $publicUrl,
         private readonly array $relevantProperties,
         private readonly array $updatedFields
     ) {}