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

Author: renovate[bot]

.github/workflows/github-pages.yaml

@@ -29,7 +29,7 @@ jobs:
 
       - uses: bazelbuild/setup-bazelisk@v3
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.13"
 
@@ -61,7 +61,7 @@ jobs:
       - name: Inspect docs site directory structure
         run: find ${{ github.workspace }}/docs/generated -maxdepth 2
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.13"
       - run: |