minor #13162 Fix phpdoc and coding standards (stof)

This PR was merged into the 2.3 branch.

Discussion
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Fix phpdoc and coding standards

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | ~
| License       | MIT
| Doc PR        | ~

This removes the unused use statements which were not catched by PHP-CS-Fixer because of string occurences. It also fixes some invalid phpdoc (scalar is not recognized as a valid type for instance).

This is complementary to symfony/symfony#13134

Commits
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8cc3f6a Fix phpdoc and coding standards

Author: fabpot

RegistryInterface.php

@@ -12,7 +12,6 @@
 namespace Symfony\Bridge\Doctrine;
 
 use Doctrine\Common\Persistence\ManagerRegistry as ManagerRegistryInterface;
-use Doctrine\ORM\Configuration;
 use Doctrine\ORM\EntityManager;
 
 /**

Tests/DependencyInjection/CompilerPass/RegisterEventListenersAndSubscribersPassTest.php

@@ -25,7 +25,7 @@ protected function setUp()
     }
 
     /**
-     * @expectedException InvalidArgumentException
+     * @expectedException \InvalidArgumentException
      */
     public function testExceptionOnAbstractTaggedSubscriber()
     {
@@ -41,7 +41,7 @@ public function testExceptionOnAbstractTaggedSubscriber()
     }
 
     /**
-     * @expectedException InvalidArgumentException
+     * @expectedException \InvalidArgumentException
      */
     public function testExceptionOnAbstractTaggedListener()
     {

Tests/Validator/Constraints/UniqueEntityValidatorTest.php

@@ -22,7 +22,6 @@
 use Symfony\Bridge\Doctrine\Tests\Fixtures\AssociationEntity;
 use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
 use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntityValidator;
-use Symfony\Component\Validator\Validator;
 use Doctrine\ORM\Tools\SchemaTool;
 
 /**