Make sure type(None) is used instead of None for the type argument of isinstance.

[Sachaa-Thanasius]

Using None, whether alone or in a tuple, as the second argument of isinstance(...) raises a TypeError at runtime. It's not a valid type.

[jaraco]

This regression was added in 19e9575 (#329) (cc @Avasam). In the future, we should be careful not to change the behavior when applying type annotations, maybe even do an AST diff to highlight behavior changes hidden in a haystack of annotations.

[Avasam]

Thanks for catching the regression.

I'm not sure why that change was even done in my PR, it doesn't affect static typing in any way.

What I think happened is that I used VSCode's PyLance to autofill some -> None return type annotations, it likely autofilled with types.NoneType. Then I must've search&replaced types.NoneType to None and missed in self-review that I introduced that change.

Worst part is it's even caught by pyright/pylance >.<