CI: (deps): Bump dask from 2026.7.1 to 2026.8.0 in /ci

Bumps [dask](https://github.com/dask/dask) from 2026.7.1 to 2026.8.0.
- [Release notes](https://github.com/dask/dask/releases)
- [Changelog](https://github.com/dask/dask/blob/main/docs/release-procedure.md)
- [Commits](dask/dask@2026.7.1...2026.8.0)

---
updated-dependencies:
- dependency-name: dask
  dependency-version: 2026.8.0
  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==0.25.0
-dask==2026.7.1
+dask==2026.8.0
 netCDF4==1.7.4
 shapely==2.1.2
 boto3==1.43.14