Attempt fixing deadlocks by moving account stats update outside transaction (#9437)

* Use `update_column` instead of `update_attribute` in callback

`update_attribute` would normally cause callbacks to be called.
Called from a callback, it seems to stop further callbacks from executing.

`update_column` does the same work, but without calling callbacks or
preventing other callbacks from executing.

* Fix deadlocks by moving account stats update outside transaction