Remove unused parameter for some functions in `services/mirror` (#30724)

Suggested by gopls `unusedparams`

services/mirror/mirror.go

 	}
 	log.Trace("Doing: Update")
 
-	handler := func(idx int, bean any) error {
+	handler := func(bean any) error {
 		var repo *repo_model.Repository
 		var mirrorType SyncType
 		var referenceID int64
 	pullMirrorsRequested := 0
 	if pullLimit != 0 {
 		if err := repo_model.MirrorsIterate(ctx, pullLimit, func(idx int, bean any) error {
-			if err := handler(idx, bean); err != nil {
+			if err := handler(bean); err != nil {
 				return err
 			}
 			pullMirrorsRequested++
 	pushMirrorsRequested := 0
 	if pushLimit != 0 {
 		if err := repo_model.PushMirrorsIterate(ctx, pushLimit, func(idx int, bean any) error {
-			if err := handler(idx, bean); err != nil {
+			if err := handler(bean); err != nil {
 				return err
 			}
 			pushMirrorsRequested++

services/mirror/mirror_pull.go

 
 	log.Trace("SyncMirrors [repo: %-v]: %d branches updated", m.Repo, len(results))
 	if len(results) > 0 {
-		if ok := checkAndUpdateEmptyRepository(ctx, m, gitRepo, results); !ok {
+		if ok := checkAndUpdateEmptyRepository(ctx, m, results); !ok {
 			log.Error("SyncMirrors [repo: %-v]: checkAndUpdateEmptyRepository: %v", m.Repo, err)
 			return false
 		}
 	return true
 }
 
-func checkAndUpdateEmptyRepository(ctx context.Context, m *repo_model.Mirror, gitRepo *git.Repository, results []*mirrorSyncResult) bool {
+func checkAndUpdateEmptyRepository(ctx context.Context, m *repo_model.Mirror, results []*mirrorSyncResult) bool {
 	if !m.Repo.IsEmpty {
 		return true
 	}