docs: update changelog for InvalidChars array keys fix

Author: gr8man

user_guide_src/source/changelogs/v4.7.4.rst

@@ -32,6 +32,7 @@ Bugs Fixed
 
 - **API:** Fixed a bug in Transformers where the root request's ``fields`` and ``include`` query parameters leaked into nested transformers created inside ``include*()`` methods, causing incorrect field filtering, unexpected includes, or infinite recursion.
 - **Database:** Fixed a bug where ``updateBatch()`` could be called after Query Builder ``where()`` conditions, even though it's not supported. In this situation, now the ``DatabaseException`` is thrown.
+- **Filters:** Fixed a bug in ``InvalidChars`` filter where invalid UTF-8 or control characters in array keys were not checked.
 - **HTTP:** Fixed a bug where the User Agent library reported Safari's WebKit version instead of the browser version from the ``Version`` token.
 - **Model:** Fixed a bug in ``Model::objectToRawArray()`` where the ``$recursive`` parameter was ignored.