Add `last updated` for document (#11164)

## Summary

![image](https://github.com/user-attachments/assets/75431f9f-debe-435d-a02e-d216be7a3a01)

![image](https://github.com/user-attachments/assets/2d1b895e-4878-410e-90ff-ff8e932cbf24)
Display the last document update time, excluding any automatically
generated parts of the document, while ensuring that Google can
accurately read and recognize the webpage's time.

Note that I do not have permission to update
``requirements-insiders.txt``


Google time info
*
https://developers.google.com/search/blog/2019/03/help-google-search-know-best-date-for
*
https://developers.google.com/search/docs/appearance/structured-data/article#amp

Similar https://github.com/astral-sh/uv/pull/11162
Closes #11148
## Test Plan
uvx --with-requirements docs/requirements.txt -- mkdocs serve -f
mkdocs.public.yml --strict

![image](https://github.com/user-attachments/assets/6e8cd609-2e60-489c-97cc-fb28aa3204e0)
The correct format is actually ``2024-08-08T22:01:08Z``, but Google
Search happens to be lenient and accepts this format.

![image](https://github.com/user-attachments/assets/2ec8ce98-49ea-403b-bbd2-3d0d5630a562)

.github/workflows/publish-docs.yml

@@ -26,6 +26,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           ref: ${{ inputs.ref }}
+          fetch-depth: 0
 
       - uses: actions/setup-python@v5
         with: