bump python ci runner

Author: AngeloGiacco

.github/workflows/tests.yml

@@ -10,7 +10,7 @@ jobs:
       - name: Set up python
         uses: actions/setup-python@v4
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Bootstrap poetry
         run: |
           curl -sSL https://install.python-poetry.org | python - -y --version 1.5.1
@@ -26,7 +26,7 @@ jobs:
       - name: Set up python
         uses: actions/setup-python@v4
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Bootstrap poetry
         run: |
           curl -sSL https://install.python-poetry.org | python - -y --version 1.5.1