Restrict pytest to 'unit' tests (i.e. not hypothesis)

[max-sixty]

Currently Azure is running hypothesis tests in any test job that has hypothesis installed (found in #3285). This isn't required, since we have a separate job for hypothesis, and slows down the normal tests.

We can either exclude it in the test job or in the tests that pytest runs as specified in setup.cfg

I think adjusting pytest's test paths in setup.cfg is a more logical place: pytest is responsible for running normal / unit tests in xarray/tests, and hypothesis can run the tests in properties

[crusaderky]

That was a conscious decision based on the observation that the whole lot of the hypothesis tests was taking something like 3 seconds. Has this changed now?

[max-sixty]

Ah. Am I thinking there's a separate hypothesis job when actually there isn't?

[crusaderky]

@max-sixty there used to. I took it away.

[crusaderky]

End-to-end runtime for properties, as of the git tip, is 1.65 seconds

[max-sixty]

Great. Thanks for being ahead of me on some of these recent issues!