Update Lib/test/test_inspect/test_inspect.py

Co-authored-by: Petr Viktorin <encukou@gmail.com>

Author: serhiy-storchaka

Lib/test/test_inspect/test_inspect.py

@@ -6174,9 +6174,7 @@ def test_builtins_have_signatures(self):
                         "next", "vars"}
         no_signature |= needs_groups
         # These have unrepresentable parameter default values of NULL
-        unsupported_signature = {"anext"}
-        # These have text signatures with PEP 457 groups
-        unsupported_signature |= {"aiter", "iter"}
+        unsupported_signature = {"anext", "aiter", "iter"}
         # These need *args support in Argument Clinic
         needs_varargs = {"min", "max", "__build_class__"}
         no_signature |= needs_varargs