[DOCS] Correct example for AfterLinkIsGeneratedEvent in changelog

The method "withAttribute()" expects a string or null as second argument.

Resolves: #100801
Related: #96641
Releases: main, 12.4
Change-Id: I2b8ef43c51159bd92730edbc47b07c2350d5f399
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78895
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>

Author: brotkrueml

typo3/sysext/core/Documentation/Changelog/12.0/Feature-96641-NewPSR-14EventForModifyingLinks.rst

@@ -62,7 +62,7 @@ The corresponding event listener class:
     {
         public function __invoke(AfterLinkIsGeneratedEvent $event): void
         {
-            $linkResult = $event->getLinkResult()->withAttribute('data-enable-lightbox', true);
+            $linkResult = $event->getLinkResult()->withAttribute('data-enable-lightbox', 'true');
             $event->setLinkResult($linkResult);
         }
     }