Upgrade setup-python action to v6

Author: fabaff

.github/workflows/python.yml

@@ -18,7 +18,7 @@ jobs:
     - uses: actions/checkout@v6
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v6
       with:
         python-version: ${{ matrix.python-version }}