chore(deps): update actions/setup-python action to v6

Author: renovate[bot]

.github/workflows/pypi-publish.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - name: Checkout sources
         uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.14'
           cache: 'pip'