Update actions/setup-python action to v6

Author: renovate[bot]

.github/workflows/cd.yml

@@ -9,7 +9,7 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.13'
       - name: Install dependencies

.github/workflows/tox_ci.yml

@@ -6,7 +6,7 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       - name: Run black
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: 3.8
       - name: install black
@@ -21,7 +21,7 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       - name: Setup Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python }}
       - name: install tox