Upgrade actions/checkout and setup-python to v6

Update .github/workflows/python-package.yml to use actions/checkout@v6 and actions/setup-python@v6. Keeps the workflow up-to-date with no functional changes to Python version or caching.

Author: C-Achard

.github/workflows/python-package.yml

@@ -21,11 +21,11 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Python
         id: setup-python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.x'
           cache: 'pip'