Also do poetry install for lint

.github/workflows/lint.yml

@@ -21,6 +21,24 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
 
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
+        with:
+          version: ${{ env.POETRY_VERSION }}
+          virtualenvs-create: true
+          virtualenvs-in-project: true
+
+      - name: Load cached venv
+        id: cached-poetry-dependencies
+        uses: actions/cache@v4
+        with:
+          path: .venv
+          key: venv-${{ runner.os }}-v1-${{ hashFiles('**/poetry.lock') }}
+
+      - name: Install dependencies
+        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
+        run: poetry install --no-root --only main,test
+
       - name: Install pre-commit
         run: pip install pre-commit==${{ env.PRECOMMIT_VERSION }}