1D wavelength solution ASDF export/import

[hpparvi]

This PR adds the WavelengthSolution1D.to_asdf and WavelengthSolution1D.from_asdf methods to serialize a 1D wavelength solution into an ASDF file.

AI/LLM disclaimer: similarly to #316, I used Claude Fable to speed up the development.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.35%. Comparing base (0d2ce22) to head (70c26d5).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #317      +/-   ##
==========================================
+ Coverage   92.25%   92.35%   +0.10%     
==========================================
  Files          18       18              
  Lines        2234     2264      +30     
==========================================
+ Hits         2061     2091      +30     
  Misses        173      173              

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[tepickering]

i will give this a more thorough review later this week. the python 3.11 and RTD failures should be looked into. i would argue that we can drop 3.11 at this point.

[hpparvi]

Thanks, @tepickering! I've fixed the RDT issues and dropped support for Python 3.11.

[tepickering]

GWCS and ASDF are the way forward. need to get the rest of the community to come along...

[tepickering]

looks like we missed pruning the python 3.11 test from the CI so it's failing. good timing on dropping it, though, because astropy will drop it as well as of v8.1.