text: Title: dask-expr got merged into dask
  Body: ### What is your issue?
  
  Since v2.0.0, dask-expr is merged into the main dask package: https://github.com/dask/dask-expr/blob/v2.0/dask_expr/__init__.py
  
  xarray still pulls in dask-expr in various environments for CI: https://github.com/search?q=repo%3Apydata%2Fxarray%20dask-expr&type=code