migrate away from deprecated ioutil APIs (#7175)

Co-authored-by: Callum Waters <cmwaters19@gmail.com>
Co-authored-by: M. J. Fromberger <fromberger@interchain.io>

internal/p2p/conn/secret_connection_test.go

@@ -6,7 +6,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	mrand "math/rand"
 	"os"
@@ -229,7 +228,7 @@ func TestDeriveSecretsAndChallengeGolden(t *testing.T) {
 	if *update {
 		t.Logf("Updating golden test vector file %s", goldenFilepath)
 		data := createGoldenTestVectors(t)
-		require.NoError(t, ioutil.WriteFile(goldenFilepath, []byte(data), 0644))
+		require.NoError(t, os.WriteFile(goldenFilepath, []byte(data), 0644))
 	}
 	f, err := os.Open(goldenFilepath)
 	if err != nil {

internal/p2p/upnp/upnp.go

@@ -10,7 +10,7 @@ import (
 	"encoding/xml"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"strconv"
@@ -312,7 +312,7 @@ func (n *upnpNAT) getExternalIPAddress() (info statusInfo, err error) {
 		return
 	}
 	var envelope Envelope
-	data, err := ioutil.ReadAll(response.Body)
+	data, err := io.ReadAll(response.Body)
 	if err != nil {
 		return
 	}
@@ -374,7 +374,7 @@ func (n *upnpNAT) AddPortMapping(
 	// TODO: check response to see if the port was forwarded
 	// log.Println(message, response)
 	// JAE:
-	// body, err := ioutil.ReadAll(response.Body)
+	// body, err := io.ReadAll(response.Body)
 	// fmt.Println(string(body), err)
 	mappedExternalPort = externalPort
 	_ = response