You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: cleanup.go
    path of file: ./repos/gitea/services/actions
    
    the code of the file until where you have to start completion: // Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package actions

import (
	"context"
	"time"

	"code.gitea.io/gitea/models/actions"
	"code.gitea.io/gitea/modules/log"
	"code.gitea.io/gitea/modules/storage"
)

// Cleanup removes expired actions logs, data and artifacts
func Cleanup(taskCtx context.Context, olderThan time.Duration) error {
	// TODO: clean up expired actions logs

	// clean up expired artifacts
	ret
    
func cleanNeedDeleteArtifacts(taskCtx context.Context) error {
	for {
		artifacts, err := actions.ListPendingDeleteArtifacts(taskCtx, deleteArtifactBatchSize)
		if err != nil {
			return err
		}
		log.Info("Found %d artifacts pending deletion", len(artifacts))
		for _, artifact := range artifacts {
			if err := actions.SetArtifactDeleted(taskCtx, artifact.ID); err != nil {
				log.Error("Cannot set artifact %d deleted: %v", artifact.ID, err)
				continue
			}
			if err := storage.ActionsArtifacts.Delete(artifact.StoragePath); err != nil {
				log.Error("Cannot delete artifact %d: %v", artifact.ID, err)
				continue
			}
			log.Info("Artifact %d set deleted", artifact.ID)
		}
		if len(artifacts) < deleteArtifactBatchSize {
			log.Debug("No more artifacts pending deletion")
			break
		}
	}
	return nil
}