upgrade github action (#210)

Author: andife

.github/workflows/tests.yml

@@ -17,7 +17,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v5