Tests time out on macOS on GitHub Actions

[datho7561]

Sometimes the UI tests fail at the 'remove temp dir' step. This is a cleanup step that runs after all the tests are done. The reason of the failure is that this step sometimes times out. Investigate different methods of resolving this test failure.

[datho7561]

Also, there are other test timeouts that appear to occur only on macOS. I think it would be good to address both of these timeouts in one PR.

[datho7561]

In #382, I disabled the tests on macOS. It would be nice to figure out why they are so slow on macOS.

[datho7561]

Tests also timing out under Linux sometimes