N°6934 - Symfony 6.4 - upgrade Symfony bundles to 6.4 (#580)

* Update Symfony lib to version ~6.4.0
* Update code missing return type
* Add an iTop general configuration entry to store application secret (Symfony mandatory parameter)
* Use dependency injection in ExceptionListener & UserProvider classes

lib/symfony/console/Output/TrimmedBufferOutput.php

@@ -21,8 +21,8 @@ use Symfony\Component\Console\Formatter\OutputFormatterInterface;
  */
 class TrimmedBufferOutput extends Output
 {
-    private $maxLength;
-    private $buffer = '';
+    private int $maxLength;
+    private string $buffer = '';
 
     public function __construct(int $maxLength, ?int $verbosity = self::VERBOSITY_NORMAL, bool $decorated = false, OutputFormatterInterface $formatter = null)
     {
@@ -36,10 +36,8 @@ class TrimmedBufferOutput extends Output
 
     /**
      * Empties buffer and returns its content.
-     *
-     * @return string
      */
-    public function fetch()
+    public function fetch(): string
     {
         $content = $this->buffer;
         $this->buffer = '';
@@ -48,7 +46,7 @@ class TrimmedBufferOutput extends Output
     }
 
     /**
-     * {@inheritdoc}
+     * @return void
      */
     protected function doWrite(string $message, bool $newline)
     {