ci: test against python 3.11, and run codecov in a non-deprecated way

[consideRatio]

More about the deprecation of codecov uploader in https://github.com/codecov/codecov-action.

[tomplus]

It hits #234

[consideRatio]

@tomplus yepp, I saw Martiusweb/asynctest#163 now, suggesting that asynctest is dropped:

I believe unittest.mock.AsyncMock in combination with pytest is probably your best bet for now.

Hmmm, I lack experience here.

Ah but also from that issue:

unittest.IsolatedAsyncioTestCase is basically a drop-in replacement

[consideRatio]

Hmmm, trialing a bit and looking at the souce code, I'm not confident on how to proceed overall. asynctest is used in quite a few places and I'm not savvy with patch mock etc.

Note that we have tests in jupyterhub/kubespawner running Python 3.11 and relying on this package, so it hasn't broken down entirely at least. I'm sadly not able to allocate time the next month or two to learn and finish this PR with a migration of asynctest.

Thank you soo much for your work on this project @tomplus, it has worked great for jupyterhub/kubespawner and is helping users across the world doing research and education among other things! If left unresolved I hope to find time to help out here!

[tomplus]

Thanks for your kind words and your contribution ❤️

Let's keep this PR opened, I'll fix the tests soon and then we'll merge it.

[tomplus]

@consideRatio Sorry, while I was fixing async tests, I had to upgrade codecov too. I completely forgot about your PR and I did the same job :/

[consideRatio]

Ah no worries at all! Thank you for your work on this project!!