minor symfony#49742 [Webhook] Add readonly modifier where this possible (onEXHovia)

This PR was merged into the 6.3 branch.

Discussion
----------

[Webhook] Add readonly modifier where this possible

| Q             | A
| ------------- | ---
| Branch?       | 6.3
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       | n/a
| License       | MIT
| Doc PR        | n/a

Commits
-------

bf4ad40 [Webhook] Add readonly modifier where this possible

Author: nicolas-grekas

src/Symfony/Component/Webhook/Controller/WebhookController.php

@@ -30,8 +30,8 @@ final class WebhookController
 {
     public function __construct(
         /** @var array<string, array{parser: RequestParserInterface, secret: string}> $parsers */
-        private array $parsers,
-        private MessageBusInterface $bus,
+        private readonly array $parsers,
+        private readonly MessageBusInterface $bus,
     ) {
     }
 

src/Symfony/Component/Webhook/Server/HeaderSignatureConfigurator.php

@@ -23,8 +23,8 @@
 final class HeaderSignatureConfigurator implements RequestConfiguratorInterface
 {
     public function __construct(
-        private string $algo = 'sha256',
-        private string $signatureHeaderName = 'Webhook-Signature',
+        private readonly string $algo = 'sha256',
+        private readonly string $signatureHeaderName = 'Webhook-Signature',
     ) {
     }
 

src/Symfony/Component/Webhook/Server/HeadersConfigurator.php

@@ -22,8 +22,8 @@
 final class HeadersConfigurator implements RequestConfiguratorInterface
 {
     public function __construct(
-        private string $eventHeaderName = 'Webhook-Event',
-        private string $idHeaderName = 'Webhook-Id',
+        private readonly string $eventHeaderName = 'Webhook-Event',
+        private readonly string $idHeaderName = 'Webhook-Id',
     ) {
     }
 

src/Symfony/Component/Webhook/Subscriber.php

@@ -14,8 +14,8 @@
 class Subscriber
 {
     public function __construct(
-        private string $url,
-        #[\SensitiveParameter] private string $secret,
+        private readonly string $url,
+        #[\SensitiveParameter] private readonly string $secret,
     ) {
     }