Bump actions/setup-python from 5 to 6 (#54)

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 5 to 6.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '6'
  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/ci.yml

@@ -48,7 +48,7 @@ jobs:
             libc6-dev libc6-dev-i386 linux-libc-dev \
             linux-libc-dev:i386 lib32z1-dev ${{ matrix.cc }}
     
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         name: Setup Python 3.9
         with:
           python-version: 3.9