chore(deps): update actions/setup-python action to v6 (#424)

Co-authored-by: Daniel Sanche <d.sanche14@gmail.com>
Co-authored-by: Daniel Sanche <sanche@google.com>

Author: renovate-bot

packages/gcp-sphinx-docfx-yaml/.github/workflows/ci.yaml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies