Try upgrading Python too

Author: brandon-rhodes

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v2
       with:
-        python-version: 3.6.15
+        python-version: 3.8.16
 
     - name: Install pinned dependencies
       run: |