Merge branch '5.4' into 6.0

* 5.4: (33 commits)
  do not pass a boolean to the constructor of the Dotenv class
  [Notifier] Fix low-deps tests
  Deprecate Composer 1
  [Filesystem] Add third argument `$lockFile` to `Filesystem::appendToFile()`
  [TwigBundle] fix auto-enabling assets/expression/routing/yaml/workflow extensions
  [PhpUnitBridge] fix symlink to bridge in docker by making its path relative
  [Dotenv] Duplicate $_SERVER values in $_ENV if they don't exist
  Fix markup
  [Notifier] Add Expo bridge
  Add polish translations (#43725)
  Rename translation:update to translation:extract
  [String] Add PLURAL_MAP "zombies" -- fix #43789
  Added support for `statusCode` default parameter when loading a template directly from route using the `Symfony\Bundle\FrameworkBundle\Controller\TemplateController` controller.
  [Validator] Update validators.bs.xlf
  Cache voters that will always abstain
  [Messenger] Fix `TraceableMessageBus` implementation so it can compute caller even when used within a callback
  [Validator] Add the missing translations for Russian (ru)
  [Validator] Added missing translations for Latvian (lv)
  [Validator] Added missing translations
  [Validator] Add missing translations for Vietnamese (VI)
  ...

Author: xabbuh

Exception/UnsupportedSchemeException.php

@@ -36,6 +36,10 @@ class UnsupportedSchemeException extends LogicException
             'class' => Bridge\Esendex\EsendexTransportFactory::class,
             'package' => 'symfony/esendex-notifier',
         ],
+        'expo' => [
+            'class' => Bridge\Expo\ExpoTransportFactory::class,
+            'package' => 'symfony/expo-notifier',
+        ],
         'fakechat' => [
             'class' => Bridge\FakeChat\FakeChatTransportFactory::class,
             'package' => 'symfony/fake-chat-notifier',

Transport.php

@@ -16,6 +16,7 @@
 use Symfony\Component\Notifier\Bridge\Clickatell\ClickatellTransportFactory;
 use Symfony\Component\Notifier\Bridge\Discord\DiscordTransportFactory;
 use Symfony\Component\Notifier\Bridge\Esendex\EsendexTransportFactory;
+use Symfony\Component\Notifier\Bridge\Expo\ExpoTransportFactory;
 use Symfony\Component\Notifier\Bridge\Firebase\FirebaseTransportFactory;
 use Symfony\Component\Notifier\Bridge\FreeMobile\FreeMobileTransportFactory;
 use Symfony\Component\Notifier\Bridge\GatewayApi\GatewayApiTransportFactory;
@@ -68,6 +69,7 @@ final class Transport
         ClickatellTransportFactory::class,
         DiscordTransportFactory::class,
         EsendexTransportFactory::class,
+        ExpoTransportFactory::class,
         FirebaseTransportFactory::class,
         FreeMobileTransportFactory::class,
         GatewayApiTransportFactory::class,