changed cache key name

Author: PhilippSchmelter

.github/workflows/ci.yml

@@ -70,9 +70,9 @@ jobs:
         uses: actions/cache@v4
         with:
           path: .venv
-          key: poetry-${{ runner.os }}-${{ matrix.python-version }}-${{ hashFiles('**/poetry.lock') }}
+          key: venv-${{ runner.os }}-${{ matrix.python-version }}-${{ hashFiles('**/poetry.lock') }}
           restore-keys: |
-            poetry-${{ runner.os }}-
+            venv-${{ runner.os }}-
       #----------------------------------------------
       # install dependencies if cache does not exist
       #----------------------------------------------