Update Pytest configuration (deprecated implicit asyncio mode)

[Carreau]

This make downstream test fail.

[Carreau]

Ok, I'm confused why downstream it asks for the option and here it says the option is unknown

[blink1073]

If you're referring to IPython's downstream checks, I think the check is using the pytest config from IPython itself. In the downstream-test action in jupyterlab/maintainer-tools we made sure to put the downstream folder in a separate file hierarchy to avoid this.

[Carreau]

Thanks for the pointers I'll try to have a look.