ci: add Python version to cache key

.github/actions/setup-poetry-env/action.yml

@@ -36,7 +36,7 @@ runs:
       uses: actions/cache@v2
       with:
         path: .venv
-        key: venv-${{ runner.os }}-${{ hashFiles('poetry.lock') }}
+        key: venv-${{ runner.os }}-${{ inputs.python-version }}-${{ hashFiles('poetry.lock') }}
 
     #----------------------------------------------
     # install dependencies if cache does not exist