refactor: replace experimental maps and slices with stdlib (#20679)

The experimental functions are now available in the standard library in
Go 1.23 [1].

[1]: https://go.dev/doc/go1.23#new-unique-package

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

cmd/server-main.go

@@ -31,6 +31,7 @@ import (
 	"os/signal"
 	"path/filepath"
 	"runtime"
+	"slices"
 	"strings"
 	"syscall"
 	"time"
@@ -53,7 +54,6 @@ import (
 	"github.com/minio/minio/internal/logger"
 	"github.com/minio/pkg/v3/certs"
 	"github.com/minio/pkg/v3/env"
-	"golang.org/x/exp/slices"
 	"gopkg.in/yaml.v2"
 )