Fix for 14674: better check for integer pixel dimensions

[keflavich]

This is a minor change to fix a future deprecation warning id'd in #14764. The logic to be checked is: is the range a whole number?

xref #14674

[github-actions]

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?
• Are docs added/updated as required? If so, do they follow the Astropy documentation guidelines?
• Is rebase and/or squash necessary? If so, please provide the author with appropriate instructions. Also see "When to rebase and squash commits".
• 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.
• Is a change log needed? If yes, did the change log check pass? If no, add the "no-changelog-entry-needed" label. If this is a manual backport, use the "skip-changelog-checks" label unless special changelog handling is necessary.
• Is this a big PR that makes a "What's new?" entry worthwhile and if so, is (1) a "what's new" entry included in this PR and (2) the "whatsnew-needed" label applied?
• Is a milestone set? Milestone must be set but we cannot check for it on Actions; do not let the green checkmark fool you.
• At the time of adding the milestone, if the milestone set requires a backport to release branch(es), apply the appropriate "backport-X.Y.x" label(s) before merge.

[keflavich]

This isn't making tests pass because there are other parts of the codebase that cause the same deprecation warning. See https://github.com/astropy/astropy/actions/runs/4768953830/jobs/8478846216?pr=14676.

@pllim What would you like to do here? Maybe we could ignore the deprecation warning globally, but add an explicit check for it just in this module? Or would it be better just to integrate this PR into another one handling this warning everywhere?

[pllim]

Wow, that is crazy. Were we abusing numpy that badly?!

[pllim]

caused by numpy/numpy#10615

[pllim]

@saimn , what do you think? Should we blanket ignore or try to fix the 50+ failures before v5.3rc?

[larrybradley]

I already had a PR for this: #14671

[pllim]

@larrybradley , you plan to fix all of them? 👀

[larrybradley]

Not today!

[saimn]

@saimn , what do you think? Should we blanket ignore or try to fix the 50+ failures before v5.3rc?

I plan to do the rc end of next week so we have a bit of time. It's not critical since it's only Numpy dev but Numpy 1.25 is expected in June I guess so we will need to fix errors soon anyway.

[pllim]

Closing in favor of #14671