Bump actions/setup-python from 4 to 5 xarray-contrib/datatree#291

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4 to 5.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v4...v5)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/pypipublish.yaml

@@ -22,7 +22,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
         name: Install Python
         with:
           python-version: 3.9
@@ -48,7 +48,7 @@ jobs:
     needs: build-artifacts
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
         name: Install Python
         with:
           python-version: '3.10'