test(salary): exercise real workbook conversion through the CLI (#489)

.github/workflows/ci.yml

@@ -73,6 +73,8 @@ jobs:
       - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: ${{ matrix.python-version }}
+      - name: Install Excel integration test dependency
+        run: python -m pip install openpyxl==3.1.5
       - run: python -m unittest discover -s tests -t . -v
 
   dependency-review: