Bump actions/setup-python from 5 to 6

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

Author: dependabot[bot]

.github/workflows/ci-tests.yml

@@ -29,7 +29,7 @@ jobs:
         steps:
             - uses: actions/checkout@v4
             - name: Setup python
-              uses: actions/setup-python@v5
+              uses: actions/setup-python@v6
               with:
                   python-version: ${{ matrix.py }}
             - run: pip install tox
@@ -41,7 +41,7 @@ jobs:
         steps:
             - uses: actions/checkout@v4
             - name: Setup python
-              uses: actions/setup-python@v5
+              uses: actions/setup-python@v6
               with:
                   python-version: "3.8"
 
@@ -53,7 +53,7 @@ jobs:
         steps:
             - uses: actions/checkout@v4
             - name: Setup python
-              uses: actions/setup-python@v5
+              uses: actions/setup-python@v6
               with:
                   python-version: "3.8"
             - run: pip install tox