(feat): support for zarr-python>=3.0.0b0

[ilan-gold]

• Closes #
• Tests added
• Release note added (or unnecessary)

[codecov]

Codecov Report

Attention: Patch coverage is 70.45455% with 13 lines in your changes missing coverage. Please review.

Project coverage is 82.15%. Comparing base (3260222) to head (0840150).

Files with missing lines	Patch %	Lines
src/anndata/_io/specs/methods.py	61.53%	10 Missing ⚠️
src/anndata/_io/specs/registry.py	80.00%	2 Missing ⚠️
src/anndata/tests/helpers.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1726      +/-   ##
==========================================
- Coverage   86.93%   82.15%   -4.78%     
==========================================
  Files          40       40              
  Lines        6039     6053      +14     
==========================================
- Hits         5250     4973     -277     
- Misses        789     1080     +291     

Files with missing lines	Coverage Δ
src/anndata/_core/sparse_dataset.py	93.35% <100.00%> (+0.33%)	⬆️
src/anndata/_io/utils.py	76.66% <ø> (ø)
src/anndata/_io/zarr.py	69.62% <100.00%> (-13.93%)	⬇️
src/anndata/compat/__init__.py	72.29% <100.00%> (-12.56%)	⬇️
src/anndata/experimental/merge.py	81.02% <100.00%> (-10.77%)	⬇️
src/anndata/tests/helpers.py	81.41% <66.66%> (-12.95%)	⬇️
src/anndata/_io/specs/registry.py	94.50% <80.00%> (-1.52%)	⬇️
src/anndata/_io/specs/methods.py	85.29% <61.53%> (-3.17%)	⬇️

... and 9 files with indirect coverage changes