Add support for APE 14 WCSes in find_optimal_celestial_wcs

[astrofrog]

@pllim - could you try this out with GWCS instances?

Fix #328

[codecov]

Codecov Report

Merging #334 (5525494) into main (06cab0d) will increase coverage by 0.14%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #334      +/-   ##
==========================================
+ Coverage   93.58%   93.72%   +0.14%     
==========================================
  Files          24       24              
  Lines         717      733      +16     
==========================================
+ Hits          671      687      +16     
  Misses         46       46              

Impacted Files	Coverage Δ
reproject/mosaicking/wcs_helpers.py	100.00% <100.00%> (ø)

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[pllim]

Other than that one comment on test class inheritance, LGTM. Thanks!

[pllim]

Once this is merged and released, please let me know the release number so I can pin over at spacetelescope/jdaviz#1949 . Thanks!

[astrofrog]

@pllim - the next release is going to be a reasonably big one in terms of features etc so I need to go through and check everything is ok, it might be another week or two until a release. Hope that's ok! If you need this sooner you could always vendor the function temporarily?

[pllim]

Whoops maybe my suggestion broke the tests.

I think a couple of weeks is fine. Thanks!

[astrofrog]

Ah yes there was a reason I had it that way - will remove the commit shortly!

[pllim]

Sorry for the trouble!