Fix doc build
@mrocklin would you mind taking a look at this PR? I think it'll fix the doc build on `main`
Sorry for the noise, the error seems to be more complicated than an error in a single file, will try something else Could you add `dask-expr` to `environment.yml`. I think that's the error from what I get locally

```python
WARNING: ources... [ 95%] user_guide/scale
>>>-------------------------------------------------------------------------
Exception in /doc/source/user_guide/scale.rst at block ending on line None
Specify :okexcept: as an option in the ipython:: block to suppress this message
---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
File /opt/miniconda3/envs/pandas-dev/lib/python3.10/site-packages/dask/dataframe/__init__.py:22, in _dask_expr_enabled()
     21 try:
---> 22     import dask_expr  # noqa: F401
     23 except ImportError:

ModuleNotFoundError: No module named 'dask_expr'

During handling of the above exception, another exception occurred:

ValueError                                Traceback (most recent call last)
Cell In[33], line 1
----> 1 import dask.dataframe as dd

File /opt/miniconda3/envs/pandas-dev/lib/python3.10/site-packages/dask/dataframe/__init__.py:87
     84 except ImportError:
     85     pass
---> 87 if _dask_expr_enabled():
     88     import dask_expr as dd
     90     # trigger loading of dask-expr which will in-turn import dask.dataframe and run remainder
     91     # of this module's init updating attributes to be dask-expr
     92     # note: needs reload, incase dask-expr imported before dask.dataframe; works fine otherwise

File /opt/miniconda3/envs/pandas-dev/lib/python3.10/site-packages/dask/dataframe/__init__.py:24, in _dask_expr_enabled()
     22     import dask_expr  # noqa: F401
     23 except ImportError:
---> 24     raise ValueError("Must install dask-expr to activate query planning.")
     25 return True

ValueError: Must install dask-expr to activate query planning.

<<<-------------------------------------------------------------------------
``` @mroeschke I added the package. If you don't mind me asking, is the reason "single file" build works for me locally after fixing the `pathlib` error is because I use an old environment? 

Is there an easy way to only test with the latest environment, or the one that's the same as CI? > If you don't mind me asking, is the reason "single file" build works for me locally after fixing the pathlib error is because I use an old environment?

Are you referring to build a doc build or a single doc page? I'm not sure if it has to do with environment, but the CI runs the doc build over all files, so building a single file of the docs is not equivalent to what is run on the CI @mroeschke I think I would like to know how to update the local environment so that it'll use the latest versions as in the CI.

Currently I have `dask==2024.2.1` locally, but I think the CI fails because of the new release `dask=2024.3.0`

Looking at the commit [history](https://github.com/dask/dask/commits/main/), some changes are directly related to `dask-expr` so it's probably the reason for the failed build on CI, but I can't reproduce locally because of my old `dask` version Ah I see. In that case, if you're using a conda environment, you can run `conda env update -f environment.yml` and it _should_ update the dependency versions as well. If not, you can just recreate the environment. @mroeschke thank you for your debugging and the update command. I think this PR should be ready for review, as the "doc build" job passes in the previous commit Thanks for the quick fix here @tqa236 