minor #20476 [Validator] Fix the configuration for custom password strength estimator (stof)

This PR was merged into the 7.2 branch.

Discussion
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[Validator] Fix the configuration for custom password strength estimator

Fixes symfony/symfony#59235

`service_closure` is about building an argument being a closure **returning** that service. This is not what we need for the custom estimator, where we need to inject the estimator callable.

Commits
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8aeceab Fix the configuration for custom password strength estimator

Author: javiereguiluz

reference/constraints/PasswordStrength.rst

@@ -178,7 +178,7 @@ service to use your own estimator:
                 class: App\Validator\CustomPasswordStrengthEstimator
 
             Symfony\Component\Validator\Constraints\PasswordStrengthValidator:
-                arguments: [!service_closure '@custom_password_strength_estimator']
+                arguments: [!closure '@custom_password_strength_estimator']
 
     .. code-block:: xml
 
@@ -192,7 +192,7 @@ service to use your own estimator:
                 <service id="custom_password_strength_estimator" class="App\Validator\CustomPasswordStrengthEstimator"/>
 
                 <service id="Symfony\Component\Validator\Constraints\PasswordStrengthValidator">
-                    <argument type="service_closure" id="custom_password_strength_estimator"/>
+                    <argument type="closure" id="custom_password_strength_estimator"/>
                 </service>
             </services>
         </container>
@@ -210,5 +210,5 @@ service to use your own estimator:
             $services->set('custom_password_strength_estimator', CustomPasswordStrengthEstimator::class);
 
             $services->set(PasswordStrengthValidator::class)
-                ->args([service_closure('custom_password_strength_estimator')]);
+                ->args([closure('custom_password_strength_estimator')]);
         };