readthedocs sphinx doc is not always including `*` from signatures

[dhalbert]

Asterisks in Sphinx Python type signatures are not showing up in the generated doc, but only sometimes:
usb_cdc.c:

//| def enable(*, console: bool = True, data: bool = False) -> None:
//|     """Enable or disable each CDC device. Can be called in ``boot.py``, before USB is connected.

But sometimes it shows up:
SPI.c:

//|     def configure(self, *, baudrate: int = 100000, polarity: int = 0, phase: int = 0, bits: int = 8) -> None:
//|         """Configures the SPI bus. The SPI object must be locked.

[dhalbert]

This is some kind of problem with autoapi dropping * in signatures; I can see it in the autoapi output. But I don't know why it's doing that, and I don't see any filed issues complaining about this yet. I have a simple test case.

[dhalbert]

I reproduced this problem with a simple example and opened an an autoapi issue about this: readthedocs/sphinx-autoapi#328

[dhalbert]

This is still broken in Sphinx 5.0.0.

[jepler]

I investigated and offered a patch: readthedocs/sphinx-autoapi#340

[jepler]

We fixed this in #6449 for ourselves.