TST: Use photutils nightly wheel

[pllim]

https://github.com/astropy/photutils/pull/1834

No need for change log because this is not user-facing change.

Checklist for maintainers

• [ ] added entry in CHANGELOG.rst within the relevant release section
• [ ] updated or added relevant tests
• [ ] updated relevant documentation
• [ ] added relevant label(s)
• [ ] ran regression tests, post a link to the Jenkins job below. How to run regression tests on a PR