Enforce ruff/Pylint rules

[DimitriPapadopoulos]

• else-if-used / R5501
• consider-using-augmented-assign / R6104

TODO:

• [ ] Add unit tests and/or doctests in docstrings
• [ ] Add docstrings and API docs for any new/modified user-facing classes and functions
• [ ] New/modified features documented in docs/user-guide/*.rst
• [ ] Changes documented as a new file in changes/
• [x] GitHub Actions have all passed
• [x] Test coverage is 100% (Codecov passes)

[DimitriPapadopoulos]

I don't think release notes are needed.

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 61.74%. Comparing base (fe42655) to head (237ec3d).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2869   +/-   ##
=======================================
  Coverage   61.74%   61.74%           
=======================================
  Files          85       85           
  Lines       10179    10179           
=======================================
  Hits         6285     6285           
  Misses       3894     3894           

Files with missing lines	Coverage Δ
src/zarr/core/codec_pipeline.py	70.09% <100.00%> (ø)
src/zarr/core/group.py	70.27% <100.00%> (ø)

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