As mentioned in the comment, we probably don't need to be storing this
in the database in the first place (as it should be able to be
calculated from the other statistics we have available to us). Something
to consider when we refactor the database backend.
This reverts commit f3faad74d5, reversing
changes made to 712e7bc7bf.
Several issues arose after migrating to 5.0, including, but possibly not
limited to, performance regressions in song select, as well as failures
when attempting to save beatmaps after metadata changes in the editor.