🔧 use poetry and caching in documentation workflow

.github/workflows/documentation.yml

@@ -20,8 +20,17 @@ jobs:
         uses: actions/setup-python@v4
         with:
           python-version: "3.10"
-      - run: |
-          pip install -r dev-requirements.txt
+      - name: Install poetry
+        uses: abatilo/actions-poetry@v2
+      - name: Define a cache for the virtual environment based on the dependencies lock file
+        uses: actions/cache@v3
+        with:
+          path: ./.venv
+          key: venv-${{ hashFiles('poetry.lock') }}
+      - name: Install the package without dependencies
+        run: poetry install --no-deps
+      - name: Install documentation dependencies
+        run: poetry install --only docs
       - run: |
           cd doc
           make html