minor Sylius#14732 [Fix] Mark PHPSpec class as final (Rafikooo)

This PR was merged into the 1.13 branch.

Discussion
----------

| Q               | A                                                            |
|-----------------|--------------------------------------------------------------|
| Branch?         | 1.13 <!-- see the comment below -->                  |
| Bug fix?        | yes                                                       |
| New feature?    | no                                                      |
| BC breaks?      | no                                                      |
| Deprecations?   | no<!-- don't forget to update the UPGRADE-*.md file --> |
| License         | MIT                                                          |

<!--
 - Bug fixes must be submitted against the 1.11 or 1.12 branch
 - Features and deprecations must be submitted against the 1.13 branch
 - Make sure that the correct base branch is set

 To be sure you are not breaking any Backward Compatibilities, check the documentation:
 https://docs.sylius.com/en/latest/book/organization/backward-compatibility-promise.html
-->


Commits
-------

577dfdc [Fix] Make spec class final

src/Sylius/Bundle/ApiBundle/spec/DataPersister/ProductTaxonDataPersisterSpec.php

@@ -21,7 +21,7 @@
 use Symfony\Component\Messenger\Envelope;
 use Symfony\Component\Messenger\MessageBusInterface;
 
-class ProductTaxonDataPersisterSpec extends ObjectBehavior
+final class ProductTaxonDataPersisterSpec extends ObjectBehavior
 {
     function let(
         ContextAwareDataPersisterInterface $decoratedDataPersister,