gh-105570: Deprecate unusual ways of creating empty TypedDicts (#105780)

Deprecate two methods of creating typing.TypedDict classes with 0 fields using the functional syntax: `TD = TypedDict("TD")` and `TD = TypedDict("TD", None)`. Both will be disallowed in Python 3.15. To create a TypedDict class with 0 fields, either use `class TD(TypedDict): pass` or `TD = TypedDict("TD", {})`.