refactor and clean up delete_all method

Now that delete_all with destroy or delete_all dependency behave
the same we no longer need this conditional. This means we can remove
the new delete_all_with_dependency method I added and go straight
to delete_records from delete_all, passing :all and the dependent
directly.
Merge pull request #14985 from eileencodes/refactor-delete-all-method

refactor and clean up delete_all method