Fix alpine package files are not rebuilt (#28638) (#28665)

Backport #28638 by @lng2020

I noticed the `BuildAllRepositoryFiles` function under the Alpine folder
is unused and I thought it was a bug.
But I'm not sure about this. Was it on purpose?

Co-authored-by: Nanguan Lin <70063547+lng2020@users.noreply.github.com>

services/packages/cleanup/cleanup.go

@@ -15,6 +15,7 @@ import (
 	packages_module "code.gitea.io/gitea/modules/packages"
 	"code.gitea.io/gitea/modules/util"
 	packages_service "code.gitea.io/gitea/services/packages"
+	alpine_service "code.gitea.io/gitea/services/packages/alpine"
 	cargo_service "code.gitea.io/gitea/services/packages/cargo"
 	container_service "code.gitea.io/gitea/services/packages/container"
 	debian_service "code.gitea.io/gitea/services/packages/debian"
@@ -122,6 +123,10 @@ func ExecuteCleanupRules(outerCtx context.Context) error {
 				if err := debian_service.BuildAllRepositoryFiles(ctx, pcr.OwnerID); err != nil {
 					return fmt.Errorf("CleanupRule [%d]: debian.BuildAllRepositoryFiles failed: %w", pcr.ID, err)
 				}
+			} else if pcr.Type == packages_model.TypeAlpine {
+				if err := alpine_service.BuildAllRepositoryFiles(ctx, pcr.OwnerID); err != nil {
+					return fmt.Errorf("CleanupRule [%d]: alpine.BuildAllRepositoryFiles failed: %w", pcr.ID, err)
+				}
 			}
 		}
 		return nil