pin to a more specific version

.github/workflows/enochecker_test.yml

@@ -22,7 +22,7 @@ jobs:
     - name: Set up Python 3.9
       uses: actions/setup-python@v2
       with:
-        python-version: 3.9
+        python-version: 3.9.19
     - name: Install enochecker_test
       run: |
         python -m pip install --upgrade pip