Merge branch '6.4' into 7.0

* 6.4:
  [HttpClient][Mailer] Revert "Let curl handle transfer encoding", use HTTP/1.1 for Mailgun
  Reviewed Catalan missing translations
  [AssetMapper] Upgrade importmap polyfill
  Fix typo: synchronous -> synchronously
  [Serializer] Check if exception message in test is correct
  Ibexa is sponsoring Symfony 5.4, thanks to them! \o/
  [VarDumper] Fix `FFICaster` test to be platform-adaptable
  [String] Add `alias` case to `EnglishInflector`
  [FrameworkBundle] Throw runtime exception when trying to use asset-mapper while http-client is disabled
  [SecurityBundle] Remove unused memory users’ `name` attribute from the XSD
  [VarExporter] generate __doUnserialize() method in ProxyHelper::generateLazyProxy()
  Double check if pcntl function exists
  Add additional headers in Scaleway bridge
  [VarDumper] Fix FFI caster test
  [DependencyInjection] Add test coverage for `AutowireCallable::buildDefinition()`

Tests/Fixtures/NotNormalizableDummy.php

@@ -26,6 +26,6 @@ public function __construct()
 
     public function denormalize(DenormalizerInterface $denormalizer, $data, ?string $format = null, array $context = []): void
     {
-        throw new NotNormalizableValueException();
+        throw new NotNormalizableValueException('Custom exception message');
     }
 }

Tests/Normalizer/AbstractObjectNormalizerTest.php

@@ -893,6 +893,7 @@ public function testDenormalizeUntypedFormat()
     public function testDenormalizeUntypedFormatNotNormalizable()
     {
         $this->expectException(NotNormalizableValueException::class);
+        $this->expectExceptionMessage('Custom exception message');
         $serializer = new Serializer([new CustomNormalizer(), new ObjectNormalizer(null, null, null, new PropertyInfoExtractor([], [new PhpDocExtractor(), new ReflectionExtractor()]))]);
         $serializer->denormalize(['value' => 'test'], DummyWithNotNormalizable::class, 'xml');
     }