The fix of
MDEV-23328 introduced a background thread for killing conflicting transactions. In 10.6, thanks to the refactoring that was conducted in MDEV-24671, the high-priority ("brute-force") applier thread can kill the conflicting transactions itself, before waiting for the locks to be finally released (after the conflicting transactions have been rolled back), in the lock_wait() function.
This will also allow us to remove the Galera hack LockGGuard that had to be added in
MDEV-20612, and remove Galera-related function parameters from lock creation.