storage: stop using deprecated io/ioutil

This replaces deprecated ioutil variables and functions as follows:

* ioutil.ReadDir -> os.ReadDir
* ioutil.ReadFile -> os.ReadFile
* ioutil.TempDir -> os.MkdirTemp
* ioutil.TempFile -> os.CreateTemp
* ioutil.WriteFile -> os.WriteFile

The ReadDir conversion involves an API change, the replacement
function returns a slice of fs.DirEntry instead of fs.FileInfo.
Where appropriate, the surrounding code has been adjusted; mostly,
that means using DirEntry.Type() instead of FileInfo.Mode().
Applying this change to the IoUtil interface would mean changing its
API, so this is left for later.

Signed-off-by: Stephen Kitt <skitt@redhat.com>

pkg/volume/util/util.go

@@ -19,7 +19,6 @@ package util
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -173,7 +172,7 @@ func LoadPodFromFile(filePath string) (*v1.Pod, error) {
 	if filePath == "" {
 		return nil, fmt.Errorf("file path not specified")
 	}
-	podDef, err := ioutil.ReadFile(filePath)
+	podDef, err := os.ReadFile(filePath)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read file path %s: %+v", filePath, err)
 	}