* main: (26 commits)
  [pre-commit.ci] pre-commit autoupdate (pydata#8900)
  Bump the actions group with 1 update (pydata#8896)
  New empty whatsnew entry (pydata#8899)
  Update reference to 'Weighted quantile estimators' (pydata#8898)
  2024.03.0: Add whats-new (pydata#8891)
  Add typing to test_groupby.py (pydata#8890)
  Avoid in-place multiplication of a large value to an array with small integer dtype (pydata#8867)
  Check for aligned chunks when writing to existing variables (pydata#8459)
  Add dt.date to plottable types (pydata#8873)
  Optimize writes to existing Zarr stores. (pydata#8875)
  Allow multidimensional variable with same name as dim when constructing dataset via coords (pydata#8886)
  Don't allow overwriting indexes with region writes (pydata#8877)
  Migrate datatree.py module into xarray.core. (pydata#8789)
  warn and return bytes undecoded in case of UnicodeDecodeError in h5netcdf-backend (pydata#8874)
  groupby: Dispatch quantile to flox. (pydata#8720)
  Opt out of auto creating index variables (pydata#8711)
  Update docs on view / copies (pydata#8744)
  Handle .oindex and .vindex for the PandasMultiIndexingAdapter and PandasIndexingAdapter (pydata#8869)
  numpy 2.0 copy-keyword and trapz vs trapezoid (pydata#8865)
  upstream-dev CI: Fix interp and cumtrapz (pydata#8861)
  ...