Adapt ECS configuration

The used constant was made private and we adapt our code

ecs.php

@@ -55,9 +55,9 @@ return static function (ContainerConfigurator $containerConfigurator): void {
     ]]);
     $services->set(ClassAttributesSeparationFixer::class)->call('configure', [[
         'elements' => [
-            'const' => ClassAttributesSeparationFixer::SPACING_ONE,
-            'method' => ClassAttributesSeparationFixer::SPACING_ONE,
-            'property' => ClassAttributesSeparationFixer::SPACING_ONE,
+            'const' => 'one',
+            'method' => 'one',
+            'property' => 'one',
         ],
     ]]);
 };