fix gh actions checkout version

.github/workflows/main.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
       - uses: actions/checkout@main
       - name: Set up Python 3.10
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@main
         with:
           python-version: "3.10"
       - name: Install dependencies