Backport PR #2051 on branch 0.12.x (fix: allow writing to v3/2 store when setting is v2/3 if possible)

[meeseeksmachine]

Backport PR #2051: fix: allow writing to v3/2 store when setting is v2/3 if possible

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.56%. Comparing base (05ffe86) to head (f73a150).
⚠️ Report is 27 commits behind head on 0.12.x.

Additional details and impacted files

@@            Coverage Diff             @@
##           0.12.x    #2061      +/-   ##
==========================================
- Coverage   87.60%   85.56%   -2.05%     
==========================================
  Files          46       46              
  Lines        7052     7052              
==========================================
- Hits         6178     6034     -144     
- Misses        874     1018     +144     

Files with missing lines	Coverage Δ
src/anndata/_io/specs/methods.py	90.17% <100.00%> (-0.90%)	⬇️
src/anndata/_settings.py	94.30% <ø> (ø)
src/anndata/compat/__init__.py	80.73% <ø> (ø)

... and 6 files with indirect coverage changes