Update python-package.yml

Author: GoodManWEN

.github/workflows/python-package.yml

@@ -30,7 +30,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install flake8 pytest pytest-asyncio
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip install -r requirements.txt
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names