minor #16753 [Serializer] Skip calling ContextBuilder::toArray() when possible (chalasr)

This PR was merged into the 6.1 branch.

Discussion
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[Serializer] Skip calling `ContextBuilder::toArray()` when possible

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Leverages symfony/symfony#46179

Commits
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be1bd78 [Serializer] Skip calling `ContextBuilder::toArray()` when possible

Author: javiereguiluz

components/serializer.rst

@@ -1222,7 +1222,7 @@ you can use "context builders" to define the context using a fluent interface::
         ->withGroups(['group1', 'group2']);
 
     $contextBuilder = (new CsvEncoderContextBuilder())
-        ->withContext($contextBuilder->toArray())
+        ->withContext($contextBuilder)
         ->withDelimiter(';');
 
     $serializer->serialize($something, 'csv', $contextBuilder->toArray());

serializer.rst

@@ -185,7 +185,7 @@ To create a more complex (de)serialization context, you can chain them using the
         ->withGroups(['group1', 'group2']);
 
     $contextBuilder = (new CsvEncoderContextBuilder())
-        ->withContext($contextBuilder->toArray())
+        ->withContext($contextBuilder)
         ->withDelimiter(';');
 
     $serializer->serialize($something, 'csv', $contextBuilder->toArray());

serializer/custom_context_builders.rst

@@ -65,9 +65,10 @@ context key, you can create a dedicated context builder::
     // src/Serializer/LegacyContextBuilder
     namespace App\Serializer;
 
+    use Symfony\Component\Serializer\Context\ContextBuilderInterface;
     use Symfony\Component\Serializer\Context\ContextBuilderTrait;
 
-    final class LegacyContextBuilder
+    final class LegacyContextBuilder implements ContextBuilderInterface
     {
         use ContextBuilderTrait;