Completely remove old non-structured errors and migrate existing ones.

spec/policies/code_ocean/error_policy_spec.rb

@@ -1,41 +0,0 @@
-require 'rails_helper'
-
-describe CodeOcean::ErrorPolicy do
-  subject { described_class }
-
-  let(:error) { FactoryBot.build(:error) }
-
-  [:create?, :index?, :new?].each do |action|
-    permissions(action) do
-      it 'grants access to admins' do
-        expect(subject).to permit(FactoryBot.build(:admin), error)
-      end
-
-      it 'grants access to teachers' do
-        expect(subject).to permit(FactoryBot.build(:teacher), error)
-      end
-
-      it 'does not grant access to external users' do
-        expect(subject).not_to permit(FactoryBot.build(:external_user), error)
-      end
-    end
-  end
-
-  [:destroy?, :edit?, :show?, :update?].each do |action|
-    permissions(action) do
-      it 'grants access to admins' do
-        expect(subject).to permit(FactoryBot.build(:admin), error)
-      end
-
-      it 'grants access to authors' do
-        expect(subject).to permit(error.execution_environment.author, error)
-      end
-
-      it 'does not grant access to all other users' do
-        [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryBot.build(factory_name), error)
-        end
-      end
-    end
-  end
-end