Bump actions/setup-python from 5 to 6 (#490)

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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/branch-pr-release.yaml

@@ -20,7 +20,7 @@ jobs:
       with:
         node-version: 18.x
     - name: Set up Python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: "3.x"
     - name: Setup NPM

.github/workflows/template-schema-updater.yaml

@@ -13,7 +13,7 @@ jobs:
           repository: aws-cloudformation/aws-cloudformation-template-schema
           path: aws-cloudformation-template-schema
           ref: main
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.9'
       - name: Install Poetry