[docs] [issue17422] language reference should specify restrictions on class namespace

Guido van Rossum <guido@python.org> added the comment: As I mentioned in my response on the PR, dict *is* required to be ordered since 3.7. So I think it is okay as is. ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue17422> _______________________________________