chore: replace using internal batch package to x/sync/errgroup

In the original batch implementation, the Go() method will always start a new goroutine and then wait for the concurrency limit, which is unnecessary for the current code. x/sync/errgroup will block Go() until the concurrency limit is met, which can effectively reduce memory usage.
In addition, the original batch always saves the return value of Go(), but it is not used in the current code, which will also waste a lot of memory space in high concurrency scenarios.

component/updater/update_geo.go

@@ -9,7 +9,6 @@ import (
 	"time"
 
 	"github.com/metacubex/mihomo/common/atomic"
-	"github.com/metacubex/mihomo/common/batch"
 	"github.com/metacubex/mihomo/common/utils"
 	"github.com/metacubex/mihomo/component/geodata"
 	_ "github.com/metacubex/mihomo/component/geodata/standard"
@@ -19,6 +18,7 @@ import (
 	"github.com/metacubex/mihomo/log"
 
 	"github.com/oschwald/maxminddb-golang"
+	"golang.org/x/sync/errgroup"
 )
 
 var (
@@ -169,41 +169,25 @@ func UpdateGeoSite() (err error) {
 func updateGeoDatabases() error {
 	defer runtime.GC()
 
-	b, _ := batch.New[interface{}](context.Background())
+	b := errgroup.Group{}
 
 	if geodata.GeoIpEnable() {
 		if geodata.GeodataMode() {
-			b.Go("UpdateGeoIp", func() (_ interface{}, err error) {
-				err = UpdateGeoIp()
-				return
-			})
+			b.Go(UpdateGeoIp)
 		} else {
-			b.Go("UpdateMMDB", func() (_ interface{}, err error) {
-				err = UpdateMMDB()
-				return
-			})
+			b.Go(UpdateMMDB)
 		}
 	}
 
 	if geodata.ASNEnable() {
-		b.Go("UpdateASN", func() (_ interface{}, err error) {
-			err = UpdateASN()
-			return
-		})
+		b.Go(UpdateASN)
 	}
 
 	if geodata.GeoSiteEnable() {
-		b.Go("UpdateGeoSite", func() (_ interface{}, err error) {
-			err = UpdateGeoSite()
-			return
-		})
+		b.Go(UpdateGeoSite)
 	}
 
-	if e := b.Wait(); e != nil {
-		return e.Err
-	}
-
-	return nil
+	return b.Wait()
 }
 
 var ErrGetDatabaseUpdateSkip = errors.New("GEO database is updating, skip")