bpo-45104: Clarify when __init__ is called (pythonGH-28210)

(cherry picked from commit fa15df7)

Co-authored-by: Raymond Hettinger <rhettinger@users.noreply.github.com>

Doc/reference/datamodel.rst

@@ -1237,7 +1237,7 @@ Basic customization
    as necessary before returning it.
 
    If :meth:`__new__` is invoked during object construction and it returns an
-   instance or subclass of *cls*, then the new instance’s :meth:`__init__` method
+   instance of *cls*, then the new instance’s :meth:`__init__` method
    will be invoked like ``__init__(self[, ...])``, where *self* is the new instance
    and the remaining arguments are the same as were passed to the object constructor.