Bump actions/setup-python from 3 to 5

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 3 to 5.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v3...v5)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/CI.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.x'
       - run: pip install mistune