Proxmox 9 was released, based on Debian 13 (Trixie), with some interesting new features.
Here are the highlights: https://pve.proxmox.com/wiki/Roadmap#Proxmox_VE_9.0
Upgrade from 8 to 9 readme: https://pve.proxmox.com/wiki/Upgrade_from_8_to_9
Known issues & breaking changes: https://pve.proxmox.com/wiki/Roadmap#9.0-known-issues
Its in the release upgrade notes. There isvone command to run if you are doing lvm. All my stuff is zfs or ceph so i never ran into it