Merge branch '6.1' into 6.2

* 6.1:
  minor #17325 Fix typo (cafferata)
  Change 'ignore' element to attribute in Serializer XML example

Author: javiereguiluz

components/serializer.rst

@@ -468,9 +468,7 @@ Option 1: Using ``@Ignore`` Annotation
                 https://symfony.com/schema/dic/serializer-mapping/serializer-mapping-1.0.xsd"
         >
             <class name="App\Model\MyClass">
-                <attribute name="bar">
-                    <ignore>true</ignore>
-                </attribute>
+                <attribute name="bar" ignore="true"/>
             </class>
         </serializer>