Bump default idleConnsPerHost to control conns in time_wait (#10653)

This PR fixes a hang which occurs quite commonly at higher concurrency
by allowing following changes

- allowing lower connections in time_wait allows faster socket open's
- lower idle connection timeout to ensure that we let kernel
  reclaim the time_wait connections quickly
- increase somaxconn to 4096 instead of 2048 to allow larger tcp
  syn backlogs.

fixes #10413

cmd/bucket-targets.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"net/http"
 	"sync"
+	"time"
 
 	minio "github.com/minio/minio-go/v7"
 	miniogo "github.com/minio/minio-go/v7"
@@ -281,8 +282,9 @@ func (sys *BucketTargetSys) getRemoteTargetClient(tcfg *madmin.BucketTarget) (*m
 	creds := credentials.NewStaticV4(config.AccessKey, config.SecretKey, "")
 
 	getRemoteTargetInstanceTransportOnce.Do(func() {
-		getRemoteTargetInstanceTransport = NewGatewayHTTPTransport()
+		getRemoteTargetInstanceTransport = newGatewayHTTPTransport(1 * time.Hour)
 	})
+
 	core, err := miniogo.NewCore(tcfg.Endpoint, &miniogo.Options{
 		Creds:     creds,
 		Secure:    tcfg.Secure,