CI: (deps): Bump dask from 2025.7.0 to 2025.9.0 in /ci

Bumps [dask](https://github.com/dask/dask) from 2025.7.0 to 2025.9.0.
- [Release notes](https://github.com/dask/dask/releases)
- [Changelog](https://github.com/dask/dask/blob/main/docs/release-procedure.md)
- [Commits](dask/dask@2025.7.0...2025.9.0)

---
updated-dependencies:
- dependency-name: dask
  dependency-version: 2025.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

ci/extra_requirements.txt

@@ -1,5 +1,5 @@
 cartopy==0.24.0
-dask==2025.7.0
+dask==2025.9.0
 netCDF4==1.7.2
 shapely==2.1.1
 boto3==1.40.1