Loosen exact equality restriction

[flying-sheep]

They kept failing. Something upstream (likely numba) or Azure’s testing machines seem to have become less consistent in calculating this. This thread came across that. @ivirshup’s final statement was

This bug seems to be based on having nested parallelism and certain reductions. We can avoid it by just not having nested parallelism, which is what I've done for gearys_c.

I don’t think exact float equality is a reasonable assumption, but if we want to continue to test for it, we need to be able to force numba to be predictable or so.

Needs no release note.

Added #2688 to track this regression

[codecov]

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Additional details and impacted files

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