fix: ak.array_equal with datetimes and timedeltas with NaTs

[ikrommyd]

backend.nplike.all(left.data == right.data) does not respect equal_nan=True. We should use something that does like backend.nplike.array_equal

[github-actions]

The documentation preview is ready to be viewed at http://preview.awkward-array.org.s3-website.us-east-1.amazonaws.com/PR3921

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.34%. Comparing base (441d5bd) to head (a28ad8f).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

Files with missing lines	Coverage Δ
src/awkward/operations/ak_almost_equal.py	98.18% <ø> (ø)

... and 6 files with indirect coverage changes

[TaiSakuma]

This is great. Now, array_equal() works with NaN.

[ianna]

@ikrommyd - Thanks! A belated comment - it would look better in the release notes if the PR title did not repeat fix: fix -- I think a fix: would be enough.

[ikrommyd]

I think changing it now will be reflected on the release notes so that’s fine.