fix: correctly reference SurveyItemResponse in Subcategory report

app/models/report/subcategory.rb

@@ -23,9 +23,9 @@ module Report
                 score = subcategory.score(school:, academic_year:)
                 zone = subcategory.zone(school:, academic_year:).type.to_s.capitalize
 
-                begin_date = SurveyItemResponse.where(school:,
+                begin_date = ::SurveyItemResponse.where(school:,
                                                       academic_year:).where.not(recorded_date: nil).order(:recorded_date).first&.recorded_date&.to_date
-                end_date = SurveyItemResponse.where(school:,
+                end_date = ::SurveyItemResponse.where(school:,
                                                     academic_year:).where.not(recorded_date: nil).order(:recorded_date).last&.recorded_date&.to_date
                 date_range = "#{begin_date} - #{end_date}"