minor #13926 Update serializer.rst (atailouloute)

This PR was merged into the 5.0 branch.

Discussion
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Update serializer.rst

as of SF 5.0, the XmlEncoder does accept `$decoderIgnoredNodeTypes` as an argument but as a key in the context.

Commits
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8574f41 Update serializer.rst

Author: javiereguiluz

components/serializer.rst

@@ -830,8 +830,7 @@ always as a collection.
 .. tip::
 
     XML comments are ignored by default when decoding contents, but this
-    behavior can be changed with the optional ``$decoderIgnoredNodeTypes`` argument of
-    the ``XmlEncoder`` class constructor.
+    behavior can be changed with the optional context key ``XmlEncoder::DECODER_IGNORED_NODE_TYPES``.
 
     Data with ``#comment`` keys are encoded to XML comments by default. This can be
     changed with the optional ``$encoderIgnoredNodeTypes`` argument of the