Merge branch '6.4' into 7.0

* 6.4:
  fix used class after merge
  fix tests
  [Console] Only execute additional checks for color support if the output is a TTY
  fix aircraft inflection
  [TwigBundle] Fix configuration when 'paths' is null
  register the MailPaceTransportFactory
  [String] Correct inflection of axis
  [Security] Fix `AuthenticationUtils::getLastUsername()` returning null
  [Process] Fixed inconsistent test

Tests/ErrorProcessInitiator.php

@@ -25,7 +25,7 @@
     while (!str_contains($process->getOutput(), 'ready')) {
         usleep(1000);
     }
-    $process->signal(\SIGSTOP);
+    $process->isRunning() && $process->signal(\SIGSTOP);
     $process->wait();
 
     return $process->getExitCode();