If my theory holds true for your issue, it’s not the update itself but a bonked up btrfs filesystem.
I had this: Repaired btrfs system m2 disk, but there is something wrong with the subvolumes or the system itself
If you have nothing to backup from them, delete the latest snapshots back to the one that was working. Then redo the update and try to repair…? I did repair my btrfs. However you might want to consult #btrfs on https://web.libera.chat/ then iff yours is broken, or just to find out if.
What was causing this for me maybe was I had hourly snapshots on and then 1 or more bugged it.