Remove dependency to speed up tests

Author: tcompa

.github/workflows/ci_poetry.yml

@@ -85,7 +85,7 @@ jobs:
           key: ${{ runner.os }}-python-${{ matrix.python-version }}-venv-${{ hashFiles('**/poetry.lock') }}-tests_tasks
 
       - name: Install dependencies (including fractal-tasks extra)
-        run: poetry install --with dev --without docs --no-interaction -E fractal-tasks
+        run: poetry install --with dev --without docs --no-interaction
 
       - name: Check if manifest has changed
         run: |