feat(website): add social proof line to hero with star count and build date

Display the awesome-python repo's star count (formatted as '230k+') and
the last data refresh date below the hero CTA. Fetches the self-repo
star count by always including vinta/awesome-python in the stars fetch.
Also removes the footer date stamp, which is now surfaced in the hero.

Co-Authored-By: Claude <[email protected]>