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/api/login_test.go

@@ -7,7 +7,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -61,7 +60,7 @@ func fakeViewIndex(t *testing.T) {
 }
 
 func getBody(resp *httptest.ResponseRecorder) (string, error) {
-	responseData, err := ioutil.ReadAll(resp.Body)
+	responseData, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return "", err
 	}