Remove loop= param from asyncio.sleep() to fix tests on Python 3.10

[mgorny]

Fixes #95

[mgorny]

I've also attempted enabling GHA testing on 3.10.

[saghul]

Looks like we need to install the wheel package to make sure building works.

[mgorny]

Yeah, I'm guessing this is because either some of the low-level stuff (pip?) or GHA hasn't been yet all synced for 3.10 deprecations.

[mgorny]

Windows seems to be unhappy but I don't really know how to fix it.

[saghul]

Let's exclude it for now. Linux and macOS pass, which is a good indication :-)

I think you can add a "excludes" section to the build matrix to skip 3.10 on Windows.

[mgorny]

Let's try that but I think the wheel install stage could be causing the hangs on 3.8/3.9 jobs too.

[saghul]

Not sure why Windows is getting stuck on Python 3.8/3.9 but that's not related to your PR. Merged!