[ci] Bump actions/setup-python from 2 to 5

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 2 to 5.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v2...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>
Co-authored-by: Federico Capoano <f.capoano@openwisp.io>

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
           ref: ${{ github.event.pull_request.head.sha }}
 
       - name: Set up Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v5
         with:
           python-version: '3.x'
 

.github/workflows/publish.yml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Set up Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v5
         with:
           python-version: '3.x'