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/notifications/webhook.go

@@ -5,7 +5,7 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"time"
@@ -88,7 +88,7 @@ func (ns *NotificationService) sendWebRequestSync(ctx context.Context, webhook *
 		}
 	}()
 
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return err
 	}