minor #12093 Replace interface in custom normalizer (tony-tran)

This PR was merged into the 4.3 branch.

Discussion
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Replace interface in custom normalizer

Replace NormalizerInterface by ContextAwareNormalizerInterface to use `context` parameter in supportNormalization method

Commits
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a756044 Replace NormalizerInterface by ContextAwareNormalizerInterface to use context in supportNormalization method

Author: javiereguiluz

serializer/custom_normalizer.rst

@@ -21,10 +21,10 @@ to customize the normalized data. To do that, leverage the ``ObjectNormalizer``:
 
     use App\Entity\Topic;
     use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
-    use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+    use Symfony\Component\Serializer\Normalizer\ContextAwareNormalizerInterface;
     use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
 
-    class TopicNormalizer implements NormalizerInterface
+    class TopicNormalizer implements ContextAwareNormalizerInterface
     {
         private $router;
         private $normalizer;