pin jinja2<3.1 in ci runs with older versions of sphinx

Author: theOehrly

.github/workflows/python-app.yml

@@ -31,10 +31,12 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         SPHINX=Sphinx
+        JINJA2=jinja2
         if [[ $SPHINX_VERSION != "" ]]; then
           SPHINX="${SPHINX}==${SPHINX_VERSION}";
+          JINJA2="${JINJA2}<3.1";
         fi
-        pip install pytest pytest-cov codecov "${SPHINX}" -e .
+        pip install pytest pytest-cov codecov "${SPHINX}" "${JINJA2}" -e .
     - name: Test with pytest
       run: |
         pytest --cov=autodocsumm --cov-report=xml tests