Handle ioutil deprecations (#53526)

* replace ioutil.ReadFile -> os.ReadFile

* replace ioutil.ReadAll -> io.ReadAll

* replace ioutil.TempFile -> os.CreateTemp

* replace ioutil.NopCloser -> io.NopCloser

* replace ioutil.WriteFile -> os.WriteFile

* replace ioutil.TempDir -> os.MkdirTemp

* replace ioutil.Discard -> io.Discard

pkg/services/ldap/ldap.go

@@ -5,9 +5,9 @@ import (
 	"crypto/x509"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"math"
 	"net"
+	"os"
 	"strconv"
 	"strings"
 	"time"
@@ -101,7 +101,7 @@ func (server *Server) Dial() error {
 		for _, caCertFile := range strings.Split(server.Config.RootCACert, " ") {
 			// nolint:gosec
 			// We can ignore the gosec G304 warning on this one because `caCertFile` comes from ldap config.
-			pem, err := ioutil.ReadFile(caCertFile)
+			pem, err := os.ReadFile(caCertFile)
 			if err != nil {
 				return err
 			}