fix __bool__ docstring (GH-31301)

Misc/NEWS.d/next/Core and Builtins/2022-02-12-11-16-40.bpo-46732.3Z_qxd.rst

@@ -0,0 +1,2 @@
+Correct the docstring for the :meth:`__bool__` method. Patch by Jelle
+Zijlstra.

Objects/typeobject.c

@@ -8065,7 +8065,7 @@ static slotdef slotdefs[] = {
     UNSLOT("__abs__", nb_absolute, slot_nb_absolute, wrap_unaryfunc,
            "abs(self)"),
     UNSLOT("__bool__", nb_bool, slot_nb_bool, wrap_inquirypred,
-           "self != 0"),
+           "True if self else False"),
     UNSLOT("__invert__", nb_invert, slot_nb_invert, wrap_unaryfunc, "~self"),
     BINSLOT("__lshift__", nb_lshift, slot_nb_lshift, "<<"),
     RBINSLOT("__rlshift__", nb_lshift, slot_nb_lshift, "<<"),