Merge branch '4.0' into 4.1

* 4.0:
  [Filesystem] fix lock file permissions
  [Lock] fix lock file permissions
  [Form] Removed .form-control-label class.
  Removed .mb-0 in errors.
  Fix the detection of the Process new argument
  add @xabbuh as a code owner of the Yaml component
  improve deprecation messages
  Replace .initialism with .text-uppercase.

Author: nicolas-grekas

Store/FlockStore.php

@@ -81,7 +81,7 @@ private function lock(Key $key, $blocking)
         set_error_handler(function ($type, $msg) use (&$error) { $error = $msg; });
         if (!$handle = fopen($fileName, 'r+') ?: fopen($fileName, 'r')) {
             if ($handle = fopen($fileName, 'x')) {
-                chmod($fileName, 0444);
+                chmod($fileName, 0644);
             } elseif (!$handle = fopen($fileName, 'r+') ?: fopen($fileName, 'r')) {
                 usleep(100); // Give some time for chmod() to complete
                 $handle = fopen($fileName, 'r+') ?: fopen($fileName, 'r');