Bump xarray from 2023.5.0 to 2023.6.0

Bumps [xarray](https://github.com/pydata/xarray) from 2023.5.0 to 2023.6.0.
- [Release notes](https://github.com/pydata/xarray/releases)
- [Changelog](https://github.com/pydata/xarray/blob/main/HOW_TO_RELEASE.md)
- [Commits](pydata/xarray@v2023.05.0...v2023.06.0)

---
updated-dependencies:
- dependency-name: xarray
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

requirements_dev.txt

@@ -5,7 +5,7 @@ matplotlib==3.7.1
 numpy==1.23.5
 pyglotaran==0.7.0
 tabulate==0.9.0
-xarray==2023.5.0
+xarray==2023.6.0
 
 # Documentation dependencies
 -r docs/requirements.txt