Bump actions/setup-python from 2 to 3

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 2 to 3.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v2...v3)

---
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>

.github/workflows/deploy.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v2
         with:
           fetch-depth: '0'
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v3
         with:
           python-version: 3.x
       - run: pip install -r docs/requirements.txt