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/tsdb/graphite/graphite.go

@@ -5,7 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/url"
 	"path"
@@ -184,7 +184,7 @@ func (s *Service) QueryData(ctx context.Context, req *backend.QueryDataRequest)
 }
 
 func (s *Service) parseResponse(res *http.Response) ([]TargetResponseDTO, error) {
-	body, err := ioutil.ReadAll(res.Body)
+	body, err := io.ReadAll(res.Body)
 	if err != nil {
 		return nil, err
 	}

pkg/tsdb/graphite/graphite_test.go

@@ -2,7 +2,7 @@ package graphite
 
 import (
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"reflect"
 	"strings"
@@ -68,7 +68,7 @@ func TestFixIntervalFormat(t *testing.T) {
 		)
 		expectedFrames := data.Frames{expectedFrame}
 
-		httpResponse := &http.Response{StatusCode: 200, Body: ioutil.NopCloser(strings.NewReader(body))}
+		httpResponse := &http.Response{StatusCode: 200, Body: io.NopCloser(strings.NewReader(body))}
 		dataFrames, err := service.toDataFrames(httpResponse)
 
 		require.NoError(t, err)
@@ -101,7 +101,7 @@ func TestFixIntervalFormat(t *testing.T) {
 		)
 		expectedFrames := data.Frames{expectedFrame}
 
-		httpResponse := &http.Response{StatusCode: 200, Body: ioutil.NopCloser(strings.NewReader(body))}
+		httpResponse := &http.Response{StatusCode: 200, Body: io.NopCloser(strings.NewReader(body))}
 		dataFrames, err := service.toDataFrames(httpResponse)
 
 		require.NoError(t, err)