Bump actions/setup-python from 3 to 4 (#1208)

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 3 to 4.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v3...v4)

---
updated-dependencies:
- dependency-name: actions/setup-python
  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/mkdocs-deploy.yaml

@@ -20,7 +20,7 @@ jobs:
         with:
           fetch-depth: 0
           persist-credentials: true
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v4
         with:
           python-version: 3.x
       - run: |