Move get_documenter over from Sphinx

[pllim]

Move get_documenter over from Sphinx because it was removed upstream in sphinx-doc/sphinx#13985 . This is as suggested by Sphinx developer in #219 (comment)

Fix #219

Towards astropy/sphinx-astropy#86

[codecov]

Codecov Report

❌ Patch coverage is 82.35294% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.69%. Comparing base (f50a016) to head (1b47aca).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
sphinx_automodapi/utils.py	72.72%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #220      +/-   ##
==========================================
- Coverage   89.83%   89.69%   -0.14%     
==========================================
  Files          31       31              
  Lines        1249     1262      +13     
==========================================
+ Hits         1122     1132      +10     
- Misses        127      130       +3     

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[AA-Turner]

IIUC you only use the returned Documenter class for the objtype attribute, so I think you could simplify things here by returning retval.objtype if Sphinx 8.2 or older, and obj_type otherwise.

A

[pllim]

Thanks, but I'd rather just do what it used to do to avoid any unintentional side effect.

[bsipocz]

I would say it may be worth exploring to do the simplification suggested above, but OTOH I think we should focus on the bigger picture and spend the time exploring #147.

So let's have this in as is, and put some focus on #147

[bsipocz]

Thanks @pllim!