Investigate test failures under macOS

[datho7561]

No description provided.

[datho7561]

Some of the logs mention that the afterEach hook times out. However, our test suite doesn't define an afterEach hook. I dug around in the vscode-extension-tester code to see what hooks it defines and found this:
https://github.com/redhat-developer/vscode-extension-tester/blob/master/src/suite/runner.ts#L55

Maybe this is related? I'm not sure how to test if taking a screenshot is causing the timeout, other than maybe vendoring a version of vscode-extension-tester without the screenshot code, or modifying its code after it's installed.

If it's the screenshot that's causing the tests to timeout, then that means the test failed, since the hook doesn't try to take a screenshot unless the test fails. I'll continue to investigate to see if I can figure out what causes the test to fail.