migration symfony 5 4 (#300)

* symfony 5.4 (diff dev)

* symfony 5.4 (working)

* symfony 5.4 (update autoload)

* symfony 5.4 (remove swiftmailer mailer implementation)

* symfony 5.4 (php doc and split Global accessor class)


### Impacted packages:

composer require php:">=7.2.5 <8.0.0" symfony/console:5.4.* symfony/dotenv:5.4.* symfony/framework-bundle:5.4.* symfony/twig-bundle:5.4.* symfony/yaml:5.4.* --update-with-dependencies

composer require symfony/stopwatch:5.4.* symfony/web-profiler-bundle:5.4.* --dev --update-with-dependencies

lib/symfony/config/Definition/EnumNode.php

@@ -22,14 +22,14 @@ class EnumNode extends ScalarNode
 {
     private $values;
 
-    public function __construct($name, NodeInterface $parent = null, array $values = [])
+    public function __construct(?string $name, NodeInterface $parent = null, array $values = [], string $pathSeparator = BaseNode::DEFAULT_PATH_SEPARATOR)
     {
         $values = array_unique($values);
         if (empty($values)) {
             throw new \InvalidArgumentException('$values must contain at least one element.');
         }
 
-        parent::__construct($name, $parent);
+        parent::__construct($name, $parent, $pathSeparator);
         $this->values = $values;
     }
 
@@ -38,6 +38,9 @@ class EnumNode extends ScalarNode
         return $this->values;
     }
 
+    /**
+     * {@inheritdoc}
+     */
     protected function finalizeValue($value)
     {
         $value = parent::finalizeValue($value);
@@ -51,4 +54,12 @@ class EnumNode extends ScalarNode
 
         return $value;
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function allowPlaceholders(): bool
+    {
+        return false;
+    }
 }