Update actions/setup-python action to v6

| datasource  | package              | from | to |
| ----------- | -------------------- | ---- | -- |
| github-tags | actions/setup-python | v5   | v6 |


Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/docs-build-try.yml

@@ -16,7 +16,7 @@ jobs:
           fetch-depth: 0
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: "3.x"
 

.github/workflows/docs-build.yml

@@ -18,7 +18,7 @@ jobs:
           fetch-depth: 0
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: "3.x"