minor #51778 [Console][Form][FrameworkBundle][HttpKernel][PropertyInfo][Validator][WebProfilerBundle] Remove optional before required param (HypeMC)

This PR was merged into the 6.4 branch.

Discussion
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[Console][Form][FrameworkBundle][HttpKernel][PropertyInfo][Validator][WebProfilerBundle] Remove optional before required param

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT

I'm guessing this trick was used to make arguments nullable for PHP prior to 7.1, but since Symfony now requires at least PHP 8.1 it shouldn't be necessary any more. As far as I can tell there's no breaking change: https://3v4l.org/USkgi .

There are still four places that this is used, but I believe those to be intentional test cases:
https://github.com/symfony/symfony/blob/38506585012540306b4a7166a4812d35ad6b8a3c/src/Symfony/Component/DependencyInjection/Tests/Fixtures/includes/autowiring_classes.php#L179-L184
https://github.com/symfony/symfony/blob/38506585012540306b4a7166a4812d35ad6b8a3c/src/Symfony/Component/DependencyInjection/Tests/Fixtures/includes/MultipleArgumentsOptionalScalarNotReallyOptional.php#L8-L13
https://github.com/symfony/symfony/blob/38506585012540306b4a7166a4812d35ad6b8a3c/src/Symfony/Component/VarDumper/Tests/Caster/ReflectionCasterTest.php#L653-L655
https://github.com/symfony/symfony/blob/38506585012540306b4a7166a4812d35ad6b8a3c/src/Symfony/Component/HttpKernel/Tests/DependencyInjection/RegisterControllerArgumentLocatorsPassTest.php#L589-L598

Commits
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426c4e012a [FrameworkBundle][WebProfilerBundle][Console][Form][HttpKernel][PropertyInfo][Validator] Remove optional before required param

Author: nicolas-grekas

Tests/Functional/Bundle/TestBundle/AutowiringTypes/AutowiredServices.php

@@ -21,7 +21,7 @@ class AutowiredServices
     private EventDispatcherInterface $dispatcher;
     private CacheItemPoolInterface $cachePool;
 
-    public function __construct(Reader $annotationReader = null, EventDispatcherInterface $dispatcher, CacheItemPoolInterface $cachePool)
+    public function __construct(?Reader $annotationReader, EventDispatcherInterface $dispatcher, CacheItemPoolInterface $cachePool)
     {
         $this->annotationReader = $annotationReader;
         $this->dispatcher = $dispatcher;