all: replace uses of ioutil with io and os (#24869)

p2p/simulations/examples/ping-pong.go

@@ -19,7 +19,7 @@ package main
 import (
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"os"
 	"sync/atomic"
@@ -63,7 +63,7 @@ func main() {
 		adapter = adapters.NewSimAdapter(services)
 
 	case "exec":
-		tmpdir, err := ioutil.TempDir("", "p2p-example")
+		tmpdir, err := os.MkdirTemp("", "p2p-example")
 		if err != nil {
 			log.Crit("error creating temp dir", "err", err)
 		}
@@ -156,7 +156,7 @@ func (p *pingPongService) Run(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
 				errC <- err
 				return
 			}
-			payload, err := ioutil.ReadAll(msg.Payload)
+			payload, err := io.ReadAll(msg.Payload)
 			if err != nil {
 				errC <- err
 				return

p2p/simulations/http.go

@@ -24,7 +24,6 @@ import (
 	"fmt"
 	"html"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"strconv"
 	"strings"
@@ -112,7 +111,7 @@ func (c *Client) SubscribeNetwork(events chan *Event, opts SubscribeOpts) (event
 		return nil, err
 	}
 	if res.StatusCode != http.StatusOK {
-		response, _ := ioutil.ReadAll(res.Body)
+		response, _ := io.ReadAll(res.Body)
 		res.Body.Close()
 		return nil, fmt.Errorf("unexpected HTTP status: %s: %s", res.Status, response)
 	}
@@ -252,7 +251,7 @@ func (c *Client) Send(method, path string, in, out interface{}) error {
 	}
 	defer res.Body.Close()
 	if res.StatusCode != http.StatusOK && res.StatusCode != http.StatusCreated {
-		response, _ := ioutil.ReadAll(res.Body)
+		response, _ := io.ReadAll(res.Body)
 		return fmt.Errorf("unexpected HTTP status: %s: %s", res.Status, response)
 	}
 	if out != nil {