Merge branch '2.8' into 3.4

* 2.8:
  [Filesystem] fix lock file permissions
  add @xabbuh as a code owner of the Yaml component

Author: nicolas-grekas

LockHandler.php

@@ -83,7 +83,7 @@ public function lock($blocking = false)
 
         if (!$this->handle = fopen($this->file, 'r+') ?: fopen($this->file, 'r')) {
             if ($this->handle = fopen($this->file, 'x')) {
-                chmod($this->file, 0444);
+                chmod($this->file, 0644);
             } elseif (!$this->handle = fopen($this->file, 'r+') ?: fopen($this->file, 'r')) {
                 usleep(100); // Give some time for chmod() to complete
                 $this->handle = fopen($this->file, 'r+') ?: fopen($this->file, 'r');