Remove "embedded callbacks removed" from 9.0 release notes

Author: johnnyshields

source/whats-new.txt

@@ -148,23 +148,6 @@ Removal of Deprecated Class ``Mongoid::Errors::InvalidStorageParent``
 The deprecated class ``{+odm+}::Errors::InvalidStorageParent`` has been
 removed.
 
-``around_*`` Callbacks for Embedded Documents are Ignored
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-{+odm+} v8.x and older allow user to define ``around_*`` callbacks for embedded
-documents. Starting in v9.0, these callbacks are ignored and will not be executed.
-A warning will be printed to the console if such callbacks are defined.
-
-If you want to restore the old behavior, you can set
-``Mongoid.around_embedded_document_callbacks`` to true in your application.
-
-.. note::
-
-   Enabling ``around_*`` callbacks for embedded documents is not recommended
-   as it may cause ``SystemStackError`` exceptions when a document has many
-   embedded documents. See `MONGOID-5658
-   <https://jira.mongodb.org/browse/MONGOID-5658>`__ for more details.
-
 ``for_js`` Method is Deprecated
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~