Pin xarray to deal with polyfit/polyval regression (#1978)

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### Pull Request Checklist:
- [ ] This PR addresses an already opened issue (for bug fixes /
features)
    - This PR fixes #xyz
- [ ] Tests for the changes have been added (for bug fixes / features)
- [ ] (If applicable) Documentation has been added / updated (for bug
fixes / features)
- [x] CHANGELOG.rst has been updated (with summary of main changes)
- [ ] Link to issue (:issue:`number`) and pull request (:pull:`number`)
has been added

### What kind of change does this PR introduce?

* Pins `xarray` such that version 2024.10.0 is not compatible with
`xclim`.

### Does this PR introduce a breaking change?

Yes. `xarray` v2024.10.0 is considered to be broken according to our
configurations. The pin will stay in place until we drop `xarray` newer
than this version.

### Other information:

pydata/xarray#9690
pydata/xarray#9691

The issue is currently fixed upstream, so the next release of `xarray`
should have no issues.

CHANGELOG.rst

@@ -4,7 +4,11 @@ Changelog
 
 v0.54.0 (unreleased)
 --------------------
-Contributors to this version: Éric Dupuis (:user:`coxipi`), Pascal Bourgault (:user:`aulemahal`).
+Contributors to this version: Éric Dupuis (:user:`coxipi`), Pascal Bourgault (:user:`aulemahal`), Trevor James Smith (:user:`Zeitsperre`).
+
+Breaking changes
+^^^^^^^^^^^^^^^^
+* Due to a regression affecting symmetry of ``polyfit`` and ``polyval`` in `xarray`, `xclim` now requires `xarray>=2023.11.0,!=2024.10.0` (see: `pydata/xarray PR/9691 <https://github.com/pydata/xarray/pull/9691>`_. (:pull:`1978`).
 
 Bug fixes
 ^^^^^^^^^

environment.yml

@@ -22,7 +22,7 @@ dependencies:
   - scikit-learn >=1.1.0
   - scipy >=1.9.0
   - statsmodels >=0.14.2
-  - xarray >=2023.11.0
+  - xarray >=2023.11.0,!=2024.10.0
   - yamale >=5.0.0
   # Extras
   - fastnanquantile >=0.0.2

pyproject.toml

@@ -52,7 +52,7 @@ dependencies = [
   "scikit-learn >=1.1.0",
   "scipy >=1.9.0",
   "statsmodels >=0.14.2",
-  "xarray >=2023.11.0",
+  "xarray >=2023.11.0,!=2024.10.0",
   "yamale >=5.0.0"
 ]