Add dask-expr to conda recipe

[jrbourbeau]

Closes #8574

[jrbourbeau]

Needs conda-forge/dask-expr-feedstock#33

EDIT: or conda-forge/dask-expr-feedstock#36

[jrbourbeau]

Here's the corresponding change upstream in the dask feedstock conda-forge/dask-feedstock#251

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

    29 files  ±0      29 suites  ±0   11h 25m 21s ⏱️ + 16m 55s
 4 055 tests ±0   3 921 ✅ +2    109 💤 ±0  25 ❌  - 2 
54 888 runs  ±0  52 381 ✅ +2  2 410 💤 ±0  97 ❌  - 2 

For more details on these failures, see this check.

Results for commit 9e0e335. ± Comparison against base commit 8c93366.

♻️ This comment has been updated with latest results.

[jrbourbeau]

It looks like the needed dask-core version isn't available on the dask conda channel. @charlesbluca @quasiben do you have bandwidth to look into this further?

[charlesbluca]

Looks like the issue here is that we're trying to pull stable dask-expr which transitively pins us to stable dask-core, which is in conflict with the pinning of the nightly dask package:

 - bokeh >=2.4.2,!=3.0.*
 - cytoolz >=0.8.2
 - python >=3.9
 - jinja2 >=2.10.3
 - dask-expr >=1.0,<1.1
 - lz4 >=4.3.2
 - pandas >=1.3
 - numpy >=1.21
 - pyarrow >=7.0
 - distributed 2024.3.1a240315 py_gdf3f57ea_4
 - dask-core >=2024.3.1a.240315,<2024.3.1b

with channels:
 - dask/label/dev

The reported errors are:
- Encountered problems while solving:
-   - package dask-expr-1.0.1-pyhd8ed1ab_0 requires dask-core 2024.3.0, but none of the providers can be installed

The two options I see to get around this are either loosening the dask pinning in stable dask-expr (assuming this is undesired) or publishing dask-expr nightlies with a dask pinning that's loose enough to use here.

[charlesbluca]

With #8601 in this should be good to close - thanks for the help @jrbourbeau!

[jrbourbeau]

Closing based on #8575 (comment)