refactor: move from io/ioutil to io and os package (#1772)

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

pkg/utils/image.go

@@ -5,7 +5,7 @@ import (
 	"crypto/tls"
 	"encoding/base64"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"regexp"
 	"strings"
@@ -66,7 +66,7 @@ func ReadImageFromURL(url string) ([]byte, error) {
 
 	defer resp.Body.Close()
 
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}