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

Author: xabbuh

Transport.php

@@ -21,6 +21,7 @@
 use Symfony\Component\Mailer\Bridge\MailerSend\Transport\MailerSendTransportFactory;
 use Symfony\Component\Mailer\Bridge\Mailgun\Transport\MailgunTransportFactory;
 use Symfony\Component\Mailer\Bridge\Mailjet\Transport\MailjetTransportFactory;
+use Symfony\Component\Mailer\Bridge\MailPace\Transport\MailPaceTransportFactory;
 use Symfony\Component\Mailer\Bridge\Postmark\Transport\PostmarkTransportFactory;
 use Symfony\Component\Mailer\Bridge\Scaleway\Transport\ScalewayTransportFactory;
 use Symfony\Component\Mailer\Bridge\Sendgrid\Transport\SendgridTransportFactory;
@@ -51,6 +52,7 @@ final class Transport
         MailerSendTransportFactory::class,
         MailgunTransportFactory::class,
         MailjetTransportFactory::class,
+        MailPaceTransportFactory::class,
         MandrillTransportFactory::class,
         PostmarkTransportFactory::class,
         ScalewayTransportFactory::class,