Fix endian-dependence of test introduced in gh-16380

[mhvk]

Description

This pull request is to address a test error on big-endian systems introduced in #16380 - e.g., see
https://github.com/astropy/astropy/actions/runs/8960434431/job/24606929816

Hence, the extra CI.

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Thank you for your contribution to Astropy! 🌌 This checklist is meant to remind the package maintainers who will review this pull request of some common things to look for.

• Do the proposed changes actually accomplish desired goals?
• Do the proposed changes follow the Astropy coding guidelines?
• Are tests added/updated as required? If so, do they follow the Astropy testing guidelines?
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• Is rebase and/or squash necessary? If so, please provide the author with appropriate instructions. Also see instructions for rebase and squash.
• Did the CI pass? If no, are the failures related? If you need to run daily and weekly cron jobs as part of the PR, please apply the "Extra CI" label. Codestyle issues can be fixed by the bot.
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[mhvk]

cc @pllim: sorry for introducing the bug, but at least now you know the cron failures will be temporary!

[neutrinoceros]

I might have a slight preference for specifying an endianness where data is initialized but not a big deal. This also works !

[pllim]

Thanks!

[pllim]

Hmm but "exotic" archs still have failures. Are they related?

[neutrinoceros]

Good point, I missed that. Looks like a completely separate problem to me, more likely linked to #16346, but I'm confused why we're only seeing it here.

[neutrinoceros]

@pllim can we manually trigger weekly cron on main now just to check that the problem is reproducible outside this branch ?

[pllim]

Yes. But might take a few hours: https://github.com/astropy/astropy/actions/runs/8970422440

[pllim]

For the jobs that completed, I do see the failures on main too. Hmm...

[neutrinoceros]

Now it's there !
I think we can go ahead with this one, and I can dig into remaining failures tomorrow !

[pllim]

Just to be sure, the dask failures in pre-deps are also unrelated, right?

https://github.com/astropy/astropy/actions/runs/8962574869/job/24611632967?pr=16391

[pllim]

Yeah, it's not.

[pllim]

Approving by proxy. Thanks!

[neutrinoceros]

Yes, dask failures were solved in #16384

[pllim]

Yes, it is green now. Thanks! https://github.com/astropy/astropy/actions/runs/8974310244

[mhvk]

Thanks @pllim and @neutrinoceros!