Bump actions/setup-python from v2.1.4 to v2.2.0

Bumps [actions/setup-python](https://github.com/actions/setup-python) from v2.1.4 to v2.2.0.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v2.1.4...8c5ea631b2b2d5d8840cf4a2b183a8a0edc1e40d)

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/mkdocs.yml

@@ -14,7 +14,7 @@ jobs:
         with:
           fetch-depth: 0
 
-      - uses: actions/setup-python@v2.1.4
+      - uses: actions/setup-python@v2.2.0
         with:
           python-version: 3.x