_json: Type indent as str | None

[Levalicious]

Currently, indent is typed int | None.
As per the C code, I'm fairly certain this should be a str not an int. This matches the behavior in the python wrapper.

I think the C code actually doesn't allow it to be None either, but I haven't dug in that far.

[brianschubert]

I can confirm that all uses in _json.c do seem to assume that indent is a string, and trying to use an int raises a TypeError at runtime. LGTM :-)

Can you also update the __new__ parameter?

[brianschubert]

I think the C code actually doesn't allow it to be None either

The C code has if (self->indent != Py_None) checks to handle the None case, so I think this is fine, unless I'm missing something.

Also as a bit of a historical note, it seems that indent was actually inert up until Python 3.13 (the code in _json.c just has some TODO comments, the value never seems to be used). So for older versions, it could in theory be set to be literally any object. I don't think that's necessarily worth reflecting in the stubs though.

[Levalicious]

Done! And thank you for the context!

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉