return_value and not_a_test_method health checks strict error fix

[reaganjlee]

This addresses parts of issue #3568.

Currently, some of the tests fail because (I believe) note_deprecation causes an undefined error with Pytest before their expected FailedHealthCheck message in tests that explicitly test for return_value (and not_a_test_method). An example of this is the test_stateful_returnvalue_healthcheck test.

Example below

Edit: I can solve the majority of tests above by adding in a catch_warning, though I'm not sure whether or not editing the tests themselves would be advised

[Zac-HD]

Comments below; you'll also need to add your name to AUTHORS.rst and create a hypothesis-python/RELEASE.rst file - see recent PRs for examples. Finally, we'll want to test that accessing the deprecated attributes... emits a HypothesisDeprecationWarning, which you can do with our @checks_deprecated_behaviour decorator.

[Zac-HD]

OK... this is looking like a bit of a tarpit, because Enums turn out to have a lot of metaclass magic inside them already and so our __getattr__ method isn't actually being called, but it's also hard to override the metaclass 🤔

[Zac-HD]

OK, let's give up on deprecating the attribute access - that would have been nicer, but turns out to be way harder than expected.

Instead, we'll note_deprecation() if you pass one of the deprecated enum members to settings(suppress_health_check=...), keep them excluded from the .all() and .__iter__() methods, and trust that this will be enough to warn most users. Back to you @reaganjlee!

[reaganjlee]

So I got all() and noting deprecation when setting settings working, but I am running into a similar enum issue where iter isn't being called (when calling list(Healthcheck).
Besides that, the other thing I'd like to note is that I removed a test that mainly tested the return_value suppression

[Zac-HD]

Ugh, maybe we should monkeypatch? something like

class HealthCheck: ...

HealthCheck.__iter__ = lambda: iter(HealthCheck.all())

[reaganjlee]

This looks good besides a few (unrelated?) tests. Let me know if there's any issue with adding in a metaclass to do this as well

[Zac-HD]

Looks great! I think we're done here, with the only remaining blocker that infuriating test hang 😢

[Zac-HD]

Want to take this on as a follow-up PR?

[reaganjlee]

Sure! I can work on this after the cacheing :)