gh-87980: Fix the error message for disallowed __weakref__ slots (#25362)

Fix the error message for disallowed `__weakref__` slots.

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 16b1a3035d56f141a38237b1dc7a050100344d99..43633f044751cabd33d074ce1b2bcd8b03fe9de3 100644 (file)
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -2712,8 +2712,7 @@ type_new_visit_slots(type_new_ctx *ctx)
             if (!ctx->may_add_weak || ctx->add_weak != 0) {
                 PyErr_SetString(PyExc_TypeError,
                     "__weakref__ slot disallowed: "
-                    "either we already got one, "
-                    "or __itemsize__ != 0");
+                    "we already got one");
                 return -1;
             }
             ctx->add_weak++;