Issue #16 add a lint run to check pytest collection works

.github/workflows/lint.yaml

@@ -21,10 +21,14 @@ jobs:
     - name: Install Python dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install isort black ruff
+        python -m pip install isort black ruff pytest
     - name: isort
       run: python -m isort . --check --diff
     # - name: black
     #   run: python -m black --check --diff .
     - name: ruff
       run: ruff check .
+    - name: "pytest: check test collection"
+      run: |
+        python -m pip install .[dev]
+        pytest --collect-only