feature #58252 [Mailer] add Mailtrap bridge (kbond)

This PR was merged into the 7.2 branch.

Discussion
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[Mailer] add Mailtrap bridge

| Q             | A
| ------------- | ---
| Branch?       | 7.2
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Issues        | n/a
| License       | MIT

This adds a new mailer bridge for [Mailtrap](https://mailtrap.io/) (their sending feature - not email testing).

### Documentation
* symfony/symfony-docs#20217

### Recipe
* symfony/recipes#1338

Commits
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c811ff3d5f [Mailer] add Mailtrap bridge

Author: fabpot

DependencyInjection/FrameworkExtension.php

@@ -2647,6 +2647,7 @@ private function registerMailerConfiguration(array $config, ContainerBuilder $co
             MailerBridge\Mailchimp\Transport\MandrillTransportFactory::class => 'mailer.transport_factory.mailchimp',
             MailerBridge\Postal\Transport\PostalTransportFactory::class => 'mailer.transport_factory.postal',
             MailerBridge\Postmark\Transport\PostmarkTransportFactory::class => 'mailer.transport_factory.postmark',
+            MailerBridge\Mailtrap\Transport\MailtrapTransportFactory::class => 'mailer.transport_factory.mailtrap',
             MailerBridge\Resend\Transport\ResendTransportFactory::class => 'mailer.transport_factory.resend',
             MailerBridge\Scaleway\Transport\ScalewayTransportFactory::class => 'mailer.transport_factory.scaleway',
             MailerBridge\Sendgrid\Transport\SendgridTransportFactory::class => 'mailer.transport_factory.sendgrid',

Resources/config/mailer_transports.php

@@ -22,6 +22,7 @@
 use Symfony\Component\Mailer\Bridge\Mailjet\Transport\MailjetTransportFactory;
 use Symfony\Component\Mailer\Bridge\Mailomat\Transport\MailomatTransportFactory;
 use Symfony\Component\Mailer\Bridge\MailPace\Transport\MailPaceTransportFactory;
+use Symfony\Component\Mailer\Bridge\Mailtrap\Transport\MailtrapTransportFactory;
 use Symfony\Component\Mailer\Bridge\Postal\Transport\PostalTransportFactory;
 use Symfony\Component\Mailer\Bridge\Postmark\Transport\PostmarkTransportFactory;
 use Symfony\Component\Mailer\Bridge\Resend\Transport\ResendTransportFactory;
@@ -61,6 +62,7 @@
         'null' => NullTransportFactory::class,
         'postal' => PostalTransportFactory::class,
         'postmark' => PostmarkTransportFactory::class,
+        'mailtrap' => MailtrapTransportFactory::class,
         'resend' => ResendTransportFactory::class,
         'scaleway' => ScalewayTransportFactory::class,
         'sendgrid' => SendgridTransportFactory::class,