Bump actions/setup-python in /.github/workflows/prepare-action

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] <[email protected]>

Author: dependabot[bot]

.github/workflows/prepare-action/action.yml

@@ -15,7 +15,7 @@ runs:
       working-directory: "./ansible_collections/hifis/toolkit/"
 
     - name: "Set up Python 3.x"
-      uses: "actions/setup-python@v5"
+      uses: "actions/setup-python@v6"
       with:
         python-version-file: "./ansible_collections/hifis/toolkit/.python-version"