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/provisioning/alerting/config_reader.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io/fs"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -65,7 +66,7 @@ func (cr *rulesConfigReader) parseConfig(path string, file fs.FileInfo) (*Alerti
 	filename, _ := filepath.Abs(filepath.Join(path, file.Name()))
 	// nolint:gosec
 	// We can ignore the gosec G304 warning on this one because `filename` comes from ps.Cfg.ProvisioningPath
-	yamlFile, err := ioutil.ReadFile(filename)
+	yamlFile, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, err
 	}