minor #17620 [Form] inline the constructor (tacman)

This PR was submitted for the 6.2 branch but it was merged into the 5.4 branch instead.

Discussion
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[Form] inline the constructor

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Commits
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e435d2c inline the constructor

Author: javiereguiluz

form/data_transformers.rst

@@ -177,11 +177,8 @@ to and from the issue number and the ``Issue`` object::
 
     class IssueToNumberTransformer implements DataTransformerInterface
     {
-        private $entityManager;
-
-        public function __construct(EntityManagerInterface $entityManager)
+        public function __construct(private EntityManagerInterface $entityManager)
         {
-            $this->entityManager = $entityManager;
         }
 
         /**