CI: (deps): Bump dask from 2023.7.1 to 2023.8.0 in /ci

Bumps [dask](https://github.com/dask/dask) from 2023.7.1 to 2023.8.0.
- [Changelog](https://github.com/dask/dask/blob/main/docs/release-procedure.md)
- [Commits](dask/dask@2023.7.1...2023.8.0)

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

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

ci/test_requirements.txt

@@ -3,4 +3,4 @@ pytest==7.4.0
 pytest-mpl==0.16.1
 netCDF4==1.6.4
 coverage==7.2.7
-dask==2023.7.1
+dask==2023.8.0