Add auto retries on app-hang errors

[Cawllec]

Goal

To enable currently unstable tests to be retried without manual effort, we're adding automatic retries in the event the app-hang tests fail due to an appium error.

Note: This doesn't currently retry if the test fails due to no errors being received. While this could very well be caused by an appium issue with the app-hang tests, it could also present due to changes in the notifier code, and should be (minimally) investigated.

[Cawllec]

Note: This relies on a change to maze-runner, which hasn't yet been released. Once that's done, this will be updated to point back to the main branch of MR.

[github-actions]

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