Fix prefer-lowest build

Author: Jean85

test/EventListener/ConsoleListenerTest.php

@@ -26,7 +26,6 @@ protected function setUp()
             ->shouldBeCalled()
             ->will(function ($arguments) use ($scope): void {
                 $callable = $arguments[0];
-                Assert::assertIsCallable($callable);
 
                 $callable($scope);
             });

test/EventListener/RequestListenerTest.php

@@ -33,7 +33,6 @@ protected function setUp()
             ->shouldBeCalled()
             ->will(function ($arguments) use ($scope): void {
                 $callable = $arguments[0];
-                Assert::assertIsCallable($callable);
 
                 $callable($scope);
             });