bpo-41974: Remove complex.__float__, complex.__floordiv__, etc (GH-22593)

Remove complex special methods __int__, __float__, __floordiv__,
__mod__, __divmod__, __rfloordiv__, __rmod__ and __rdivmod__
which always raised a TypeError.
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 6ae06a5..01e5c72 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -14839,7 +14839,7 @@
             break;
         default:
             PyErr_Format(PyExc_TypeError,
-                    "%%%c format: a number is required, "
+                    "%%%c format: a real number is required, "
                     "not %.200s",
                     type, Py_TYPE(v)->tp_name);
             break;