Merge branch '6.3' into 6.4

* 6.3:
  [Finder] Fix initial directory is opened twice
  typo fix
  Fix test
  Fix some return types in tests

Author: nicolas-grekas

Tests/EventListener/ErrorListenerTest.php

@@ -140,7 +140,7 @@ public function getParameterOption($values, $default = false, $onlyParams = fals
     {
     }
 
-    public function parse()
+    public function parse(): void
     {
     }
 

Tests/Output/OutputTest.php

@@ -182,7 +182,7 @@ public function clear()
         $this->output = '';
     }
 
-    protected function doWrite(string $message, bool $newline)
+    protected function doWrite(string $message, bool $newline): void
     {
         $this->output .= $message.($newline ? "\n" : '');
     }