Fix poetry cache using the wrong file

Author: thibaudcolas

.github/workflows/ci.yml

@@ -68,7 +68,7 @@ jobs:
       - uses: actions/cache@v2
         with:
           path: ~/.cache/pip
-          key: ${{ runner.os }}-python-${{ hashFiles('**/poetry.lock') }}
+          key: ${{ runner.os }}-python-${{ hashFiles('**/pyproject.toml') }}
           restore-keys: |
             ${{ runner.os }}-python-
       - run: |