[3.13] gh-101291: Add versionadded directives for PyUnstable_Long_* (GH-125384) (#125407)

gh-101291: Add versionadded directives for PyUnstable_Long_* (GH-125384)
(cherry picked from commit c6d7b64)

Co-authored-by: Sergey B Kirpichev <[email protected]>

Author: miss-islington

Doc/c-api/long.rst

@@ -538,10 +538,15 @@ distinguished from a number.  Use :c:func:`PyErr_Occurred` to disambiguate.
    Exactly what values are considered compact is an implementation detail
    and is subject to change.
 
+   .. versionadded:: 3.12
+
+
 .. c:function:: Py_ssize_t PyUnstable_Long_CompactValue(const PyLongObject* op)
 
    If *op* is compact, as determined by :c:func:`PyUnstable_Long_IsCompact`,
    return its value.
 
    Otherwise, the return value is undefined.
 
+   .. versionadded:: 3.12
+