chore: add deprecation of copy_on_write_X

[ilan-gold]

• Closes #
• Tests added

• Release note not necessary because: Dev change

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.69%. Comparing base (c87dc0a) to head (6f956fa).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2448   +/-   ##
=======================================
  Coverage   85.69%   85.69%           
=======================================
  Files          49       49           
  Lines        7793     7794    +1     
=======================================
+ Hits         6678     6679    +1     
  Misses       1115     1115           

Files with missing lines	Coverage Δ
src/anndata/_settings.py	92.63% <100.00%> (+0.04%)	⬆️