Fix working with --stepwise

[adamchainz]

Python Version

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Package Version

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Description

https://docs.pytest.org/en/6.2.x/cache.html#stepwise

Using --stepwise doesn't seem to work with pytest-randomly at current.

If I have tests A through D that all fail with 'assert 0', but a seed that runs them with D first, it stops after the failure of D but assumes that A through C passed even though they didn't run.

It seems to base its success/fail tracking on the test order pre-shuffle.