Include version annotation for PyObject_Call().

Doc/api/abstract.tex

@@ -236,6 +236,7 @@ determination.
   expression \samp{apply(\var{callable_object}, \var{args}, \var{kw})}
   or \samp{\var{callable_object}(*\var{args}, **\var{kw})}.
   \bifuncindex{apply}
+  \versionadded{2.2}
 \end{cfuncdesc}