remove an unneeded failing legacy test

The removed test is not needed anymore as it is already covered by the
`testEnabledStrictEmailOptionIsMappedToStrictEmailValidationMode` and
`testDisabledStrictEmailOptionIsMappedToLooseEmailValidationMode` tests.

Author: xabbuh

Tests/DependencyInjection/Fixtures/php/validation_strict_email.php

@@ -758,13 +758,6 @@ public function testValidationTranslationDomain()
         $this->assertSame('messages', $container->getParameter('validator.translation_domain'));
     }
 
-    public function testValidationStrictEmail()
-    {
-        $container = $this->createContainerFromFile('validation_strict_email');
-
-        $this->assertTrue($container->getDefinition('validator.email')->getArgument(0));
-    }
-
     public function testValidationMapping()
     {
         $container = $this->createContainerFromFile('validation_mapping');