Debian 12 bookworm upgrade
The next step after the %Debian 11 bullseye upgrade is, of course, the Debian 12 "bookworm" upgrade. That release should happen some time in 2023. Given that bullseye was released in summer of 2021, it's logical to expect it to become EOL by summer of 2024.
We typically start upgrading our boxes when testing enter freeze, so we might even want to start working on this in early 2023, setting the start date accordingly.