refactor: upgrade github actions

Author: mjs1995

.github/workflows/pytest.yml

@@ -17,10 +17,10 @@ jobs:
 
     steps:
       - name: Check out code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Setup Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python }}