Update cmethods.adjust's type annotations

[btschwertfeger]

• Updating the type annotation, since the function only works well with xarray.core.dataarray.DataArray.
• Update pre-commit hooks

[codecov]

Codecov Report

Attention: Patch coverage is 92.30769% with 1 line in your changes missing coverage. Please review.

Project coverage is 95.88%. Comparing base (3addde7) to head (04aca9e).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
cmethods/core.py	75.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #155      +/-   ##
==========================================
- Coverage   96.17%   95.88%   -0.30%     
==========================================
  Files           7        7              
  Lines         314      316       +2     
==========================================
+ Hits          302      303       +1     
- Misses         12       13       +1     

Flag	Coverage Δ
unittests	95.88% <92.30%> (-0.30%)	⬇️

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Files with missing lines	Coverage Δ
cmethods/__init__.py	92.00% <100.00%> (+0.16%)	⬆️
cmethods/utils.py	96.55% <100.00%> (ø)
cmethods/core.py	90.56% <75.00%> (-1.75%)	⬇️