gh-114803: Mention that @dataclass should not be applied on enums

Doc/howto/enum.rst

@@ -497,13 +497,23 @@ the :meth:`~Enum.__repr__` omits the inherited class' name.  For example::
     >>> Creature.DOG
     <Creature.DOG: size='medium', legs=4>
 
-Use the :func:`!dataclass` argument ``repr=False``
+Use the :func:`~dataclasses.dataclass` argument ``repr=False``
 to use the standard :func:`repr`.
 
 .. versionchanged:: 3.12
    Only the dataclass fields are shown in the value area, not the dataclass'
    name.
 
+.. note::
+
+   Adding :func:`~dataclasses.dataclass` decorator to :type:`Enum`
+   and its subclasses is not supported. It will not raise any errors,
+   but it will produce very strange results at runtime::
+
+      @dataclass  # don't do this: it does not make any sense
+      class Colors(Enum):
+         red = 'red'
+
 
 Pickling
 --------