Bump actions/setup-python from 2.2.2 to 2.3.1

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 2.2.2 to 2.3.1.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v2.2.2...v2.3.1)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

.github/workflows/ci.yml

@@ -33,7 +33,7 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Install Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2.2.2
+        uses: actions/setup-python@v2.3.1
         with:
           python-version: ${{ matrix.python-version }}
 
@@ -58,7 +58,7 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Install Python 3.9
-        uses: actions/setup-python@v2.2.2
+        uses: actions/setup-python@v2.3.1
         with:
           python-version: 3.9