build: update checkout and setup-python actions to v6

Author: thebaptiste

.github/workflows/ci.yml

@@ -16,9 +16,9 @@ jobs:
     name: Python ${{ matrix.python-version }}
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies