Typing hints: add "| None" to function/method arguments that take a None default value.

[rodrigobr-msft]

There are many functions/methods that have parameters with default values of None but whose typing annotations do not include None. Example:

@staticmethod
    def attachment(
        attachment: Attachment,
        text: str = None,
        speak: str = None,
        input_hint: InputHints | str = None,
    ):

while the correction would be:

@staticmethod
    def attachment(
        attachment: Attachment,
        text: str | None = None,
        speak: str | None = None,
        input_hint: InputHints | str | None = None,
    ):