CI failing because astropy 7.0 deprecated "Fits"

[pllim]

Example log: https://github.com/astropy/specutils/actions/runs/12041463576/job/33573385019

Not sure how we missed it during RC testing... 🧐

specutils\tests\test_loaders.py::test_tabular_fits_autowrite -
astropy.utils.exceptions.AstropyDeprecationWarning:
The class "Fits" has been renamed to "FITS" in version 7.0.
The old name is deprecated and may be removed in a future version.
        Use FITS instead.

Blocked by:

• Need a new gwcs release spacetelescope/gwcs#539

[pllim]

Maybe the bug is here somewhere but I cannot find it at a glance. 🤷‍♀️

https://github.com/astropy/specutils/blob/main/specutils/io/default_loaders/tabular_fits.py

[dhomeier]

It's from gwcs https://github.com/astropy/specutils/actions/runs/12138511071/job/33844133922?pr=1199#step:5:220
and fixed in spacetelescope/gwcs#508 but unreleased yet. Thus py312-test-devdeps was already passing.

[pllim]

This is bad. GWCS needs to release.

spacetelescope/gwcs#508 (comment)