import datatree from xarray

[melonora]

Minor change of import in order to account for xarray including DataTree now.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 45.31%. Comparing base (cff4896) to head (ed60d9f).
Report is 20 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #232      +/-   ##
==========================================
- Coverage   45.50%   45.31%   -0.20%     
==========================================
  Files          22       22              
  Lines        2149     2143       -6     
==========================================
- Hits          978      971       -7     
- Misses       1171     1172       +1     

Files with missing lines	Coverage Δ
src/spatialdata_io/_constants/_enum.py	71.42% <100.00%> (-9.06%)	⬇️
src/spatialdata_io/_docs.py	78.57% <100.00%> (+1.64%)	⬆️
src/spatialdata_io/_utils.py	78.26% <100.00%> (+0.98%)	⬆️
src/spatialdata_io/readers/_utils/_read_10x_h5.py	85.10% <100.00%> (ø)
src/spatialdata_io/readers/_utils/_utils.py	40.74% <100.00%> (-1.89%)	⬇️
src/spatialdata_io/readers/cosmx.py	18.93% <100.00%> (ø)
src/spatialdata_io/readers/dbit.py	18.69% <ø> (-0.66%)	⬇️
src/spatialdata_io/readers/merscope.py	24.06% <100.00%> (ø)
src/spatialdata_io/readers/steinbock.py	42.22% <100.00%> (ø)
src/spatialdata_io/readers/stereoseq.py	16.21% <100.00%> (ø)
... and 2 more