Use PHP 7.4 on deps=low

Author: nicolas-grekas

Tests/Resource/ClassExistenceResourceTest.php

@@ -76,6 +76,8 @@ public function testExistsKo()
     }
 
     /**
+     * @group issue-32995
+     *
      * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
      */
     public function testBadParentWithTimestamp()
@@ -85,6 +87,8 @@ public function testBadParentWithTimestamp()
     }
 
     /**
+     * @group issue-32995
+     *
      * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
      */
     public function testBadParentWithNoTimestamp()