minor #20382 [Serializer] remove note about the reverted Default group change (xabbuh)

This PR was merged into the 7.1 branch.

Discussion
----------

[Serializer] remove note about the reverted Default group change

revert #19526 as symfony/symfony#51514 was reverted in symfony/symfony#58705

Commits
-------

626d56e remove note about the reverted Default group change

Author: javiereguiluz

serializer.rst

@@ -385,18 +385,6 @@ stored in one of the following locations:
 * All ``*.yaml`` and ``*.xml`` files in the ``Resources/config/serialization/``
   directory of a bundle.
 
-.. note::
-
-    The groups used by default when normalizing and denormalizing objects are
-    ``Default`` and the group that matches the class name. For example, if you
-    are normalizing a ``App\Entity\Product`` object, the groups used are
-    ``Default`` and ``Product``.
-
-    .. versionadded:: 7.1
-
-        The default use of the class name and ``Default`` groups when normalizing
-        and denormalizing objects was introduced in Symfony 7.1.
-
 .. _serializer-enabling-metadata-cache:
 
 Using Nested Attributes