chore: update golangci-lint to v2.13.0

Migrate the deprecated gofumpt `extra-rules` to `extra.group-params`, as
the alias now also enables the new `clothe-returns` and `balance-calls`
rules. Disable SA4023, which hangs on go 1.27, see
https://github.com/golangci/golangci-lint/issues/6732.

Apply the resulting modernize fixes, mostly flattening embedded struct
literals and switching errors.As to errors.AsType.

Assisted-by: Claude:Opus 5

services/packages/alpine/repository.go

@@ -333,10 +333,8 @@ func buildPackagesIndex(ctx context.Context, ownerID int64, repoVersion *package
 		ctx,
 		repoVersion,
 		&packages_service.PackageFileCreationInfo{
-			PackageFileInfo: packages_service.PackageFileInfo{
-				Filename:     IndexArchiveFilename,
-				CompositeKey: fmt.Sprintf("%s|%s|%s", branch, repository, architecture),
-			},
+			Filename:          IndexArchiveFilename,
+			CompositeKey:      fmt.Sprintf("%s|%s|%s", branch, repository, architecture),
 			Creator:           user_model.NewGhostUser(),
 			Data:              signedIndexContent,
 			IsLead:            false,