Update actions/checkout action to v5

Author: renovate[bot]

.github/workflows/python-package.yml

@@ -9,7 +9,7 @@ jobs:
       max-parallel: 5
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v5
     - name: Set up Python 3.8
       uses: actions/setup-python@v2
       with: