Tor Browser 13.5 support article: September 2025 update

The current support page https://support.torproject.org/tbb/tor-browser-and-legacy-os/ talks about how Tor Browser support will end in the future, including:

Users on [OS] will continue receiving security updates for Tor Browser 13.5 for a limited time until at least September of 2025.

This article should be updated to reflect the new situation once we reach September. @morgan or @pierov can you give the details?