Revert extra validation for duplication between same keys on a submit

app/services/ci/create_pipeline_schedule_service.rb

 module Ci
   class CreatePipelineScheduleService < BaseService
     def execute
-      pipeline_schedule = project.pipeline_schedules.build(pipeline_schedule_params)
-
-      if variable_keys_duplicated?
-        pipeline_schedule.errors.add('variables.key', "keys are duplicated")
-
-        return pipeline_schedule
-      end
-
-      pipeline_schedule.save
-      pipeline_schedule
-    end
-
-    def update(pipeline_schedule)
-      if variable_keys_duplicated?
-        pipeline_schedule.errors.add('variables.key', "keys are duplicated")
-
-        return false
-      end
-
-      pipeline_schedule.update(pipeline_schedule_params)
+      project.pipeline_schedules.create(pipeline_schedule_params)
     end
 
     private
 
     def pipeline_schedule_params
-      @pipeline_schedule_params ||= params.merge(owner: current_user)
-    end
-
-    def variable_keys_duplicated?
-      attributes = pipeline_schedule_params['variables_attributes']
-      return false unless attributes.is_a?(Array)
-
-      attributes.map { |v| v['key'] }.uniq.length != attributes.length
+      params.merge(owner: current_user)
     end
   end
 end