Merge branch '6.4' into 7.1

* 6.4:
  serializer[custom_normalizer]: fix reference to built-in normalizers
  Update custom_constraint.rst

Author: javiereguiluz

serializer/custom_normalizer.rst

@@ -3,7 +3,7 @@ How to Create your Custom Normalizer
 
 The :doc:`Serializer component </serializer>` uses normalizers to transform
 any data into an array. The component provides several
-ref:`built-in normalizers <serializer-built-in-normalizers>` but you may
+:ref:`built-in normalizers <serializer-built-in-normalizers>` but you may
 need to create your own normalizer to transform an unsupported data
 structure.
 

validation/custom_constraint.rst

@@ -495,7 +495,7 @@ A class constraint validator must be applied to the class itself:
 
         use App\Validator as AcmeAssert;
 
-        #[AcmeAssert\ProtocolClass]
+        #[AcmeAssert\ConfirmedPaymentReceipt]
         class AcmeEntity
         {
             // ...