Another attempt at the correct python version

Author: dixonjoel

.github/workflows/test_actions.yml

@@ -230,8 +230,10 @@ jobs:
         uses: ./setup-poetry
       - name: Create project
         run: poetry new test-project
-      - name: Set compatible Python version in pyproject.toml
-        run: poetry env use ${{ matrix.python-version }} -C test-project
+      - name: Restrict Python version in pyproject.toml
+        run: |
+          poetry run poetry env use ${{ matrix.python-version }} -C test-project
+          poetry run poetry add 'python@>=3.7,<4.0' --dev -C test-project
       - name: Add ni-python-styleguide to the project
         run: poetry add ni-python-styleguide -C test-project
       - name: Create poetry.lock